Method and facility for separating and recovering steel pipe and covering resin in resin-covered steel pipe

ABSTRACT

There are provided a method and a facility for separating and recovering a steel pipe and a covering resin in a resin-covered steel pipe, which do not produce cuttings of the steel pipe and which make it possible to continuously operate the facility. The method comprises the steps of using a cut line forming means installed forwardly of the position that a high frequency induction coil passes, so as to form a cut line extending from the surface of the resin-covered steel pipe toward the steel pipe, deep enough to reach the surface of the steel pipe from the surface of the covering resin, throughout the length of the resin-covered steel pipe, circumferentially dividing the covering resin into at least two parts, heating the steel pipe by high frequency induction heating, in the position of a separating device disposed at a suitable position immediately after the passage of the position of the high frequency induction coil, to the extent the boundary between the covering resin and the steel pipe assumes the state for the release of the covering resin from the steel pipe, and cutting each covering resin into at least two parts along the cut line and toward the outside of the steel pipe by the separating device while releasing and separating it from the steel pipe.

FIELD OF SEARCH

This invention belongs to the field of technology pertaining to methodand apparatuses for reusing resin-coated steel pipes collected as wasteor recycling resources, or more particularly, relates to a method and anapparatus for recovering materials through the separation and recoveringof steel pipe and coating resin in segregated condition fromresin-coated steel pipe that is produced by adhering a thermo-plasticresin on the pipe surface.

BACKGROUND OF THE INVENTION

As a previous method to separate and recover steel pipe and coatingresin, the technique for which the present applicant was granted patentstatus in Japan is disclosed in Japanese Patent No.2533465.

The technique according to the above-named Japanese patent has beenpreferably used for resin-coated steel pipe that consist of pipe havinga thickness about 0.8 mm and outer diameter of 25.5–40 mm, and a coatingof a thermo-plastic synthetic resin, such as acrylonitrile acryl styrene(AAS) or acrylonitrile butadiene styrene (ABS), of a uniform thicknessof about 1 mm fixed on the steel pipe surface with a thin film ofadhesive.

The means to separate and recover a steel pipe and coating resin, asdescribed in the above Japanese patent, consists of passing aresin-coated steel pipe through or near a high-frequency induction coilby feed rolls and take-up rolls, and heating the pipe to a temperatureno lower than the melting point of the resin.

Further, as stated in Claims 1 and 2 and shown in FIGS. 2 through 5 ofthe above Japanese patent, the coating resin is scraped off into chipsof a certain size by scraping rolls, which are used as a separatingmechanism located at a position where the inner layer of coating ismelted and the outer layer is in a softened condition after passing thehigh-frequency induction coil, and which rotate in the feeding directionof the pipe. The scraping rolls are provided with blades that fit theshape of the pipe section (circular in FIGS. 2 and 3; square in FIGS. 4and 5 of the above Japanese patent) and are arranged at a pitchcorresponding to the size of the scraped resin chips.

Further, as stated in Claim 3 and shown in FIG. 6 of the above Japanesepatent, the scraping rolls, used as a separating mechanism located at aposition where the inner layer of coating is melted and the outer layeris in a softened condition after passing the high-frequency inductioncoil, are rotated in the direction opposite to the feeding direction ofthe pipe to scrape off the resin into a set of long strips. Here again,the scraping rolls are provided with blades fitting the shape of thepipe section.

Still further, as stated in Claim 4 and shown in FIG. 7 of the aboveJapanese patent, coating resin is scraped into long strips by scrapingblades used for separating and fixed at a position where the inner layerof coating is melted and the outer layer is in a softened conditionafter passing the high-frequency induction coil.

In Claims 1, 3 and 4 of the above Japanese patent, steel pipe and resinfrom a resin-coated steel pipe are separated by scraping and arerecovered in a segregated condition. For this purpose, at least one pairof scraping blades, opposing each other, are formed into a shapecongruent with the outer periphery of the steel pipe when seen from thedirection perpendicular to the axis of the pipe.

In order for each of the blades to scrape coating resin from theresin-coated steel pipe into chips of a certain size (from about 10mm×10 mm to 10 mm×15 mm) or into a set of long strips, it is importantthat the patent is practiced in such a manner that the blade tips arefitted tightly on the outer periphery of the pipe during the feedingmotion for the pipe. But the fact that the tips of each of the bladesare formed into a shape congruent with the outer periphery of the steelpipe and must be fitted tightly on the outer periphery of the pipeduring the feeding motion, poses the following problems.

Firstly, small pieces or dust (about 1 mm×1 mm through 1 mm×5 mm insize) of steel cut off from steel pipe are mingled with the scraped offresin. This means that in order to reuse the resin separated andrecovered from the steel pipe, an additional process and additionalequipment to remove the steel pieces or dust from the recovered resinare required.

Secondly, the tips of the scraping blades come in contact with themelted inner layer of coating resin and, in case the apparatus is runcontinuously, the tips of the blades generate friction heat and raisetemperature to a point higher than desirable as they tightly engage withthe outer surface of the steel pipe that is moving in the feedingdirection, and thus, part of the resin heated over the melting point andseparated from steel pipe will gradually stick to the tips of the bladesand accumulate. When the resin thus accumulated gradually reaches acertain amount, it must be removed from around the tips of the blades,which means an interruption of continuous run of the apparatus.

The primary object of the present invention, therefore, is to provide amethod and an apparatus to separate and recover steel pipe and coatingresin from resin-coated steel pipe that make it possible to separatecoating resin from the steel pipe without scraping, and hence, withoutgenerating cut off dust of steel pipe, and thereby make it possible torun the apparatus continuously.

DISCLOSURE OF THE INVENTION

To achieve the objects described above, the invention as recited inClaim 1 relates to a method to separate and recover steel pipe andcoating resin from resin-coated steel pipe, intended to process aresin-coated steel pipe (1) which consists of steel pipe (2) and coatingresin (3) adhered to an outer surface of said pipe, employing aseparating and recovering apparatus having a feeding device (10), ahigh-frequency induction heating device (20), a separating mechanism(25), a take-up device (30) and a recovering device (40), said feedingdevice (10) feeding said resin-coated steel pipe (1) of certain lengthin a running direction thereof thereby passing and heating saidresin-coated steel pipe (1) inside or near a high-frequency inductioncoil (21) of said high-frequency induction heating device (20), saidseparating mechanism, which is located at a certain position reachedimmediately after a heating process separating said coating resin (3)from said steel pipe (2), said take-up device (30) taking up said steelpipe (2) in said running direction thereof and said recovering device(40) recovering separated steel pipe (2) and coating resin (3), ischaracterized in that

a cutting means located at a position before said high-frequencyinduction coil (21) makes incision lines (18) in said coating resin (3)that reach in depth from a surface of said coating resin (3) to asurface of said steel pipe (2) and extend throughout a length of saidresin-coated pipe (1) at positions that divide a periphery of saidcoating resin into at least two parts, that

by means of high-frequency induction heating, said steel pipe (2) isheated in such a manner that, when it reaches said separating mechanism(25) located at an appropriate position arrived at immediately after aheating process, a bottom layer of said coating resin (3) adjacent to aboundary of said steel pipe reaches a condition separable from saidsteel pipe (2), and that

said separating mechanism (25) separates said coating resin (3) fromsaid steel pipe (2) and severs said coating resin (3) along incisionlines (18) and away from said resin-coated steel pipe (1) into at leasttwo pieces.

The invention as recited in Claim 2 relates to a method to separate andrecover steel pipe and coating resin from resin-coated steel pipe,intended to process a resin-coated steel pipe (1) which consists ofsteel pipe (2) and coating resin (3) adhered to an outer surface of saidpipe, employing a separating and recovering apparatus having a feedingdevice (10), a high-frequency induction heating device (20), aseparating mechanism (25), a take-up device (30) and a recovering device(40), said feeding device (10) feeding said resin-coated steel pipe (1)of certain length in a running direction thereof thereby passing andheating said resin-coated steel pipe (1) inside or near a high-frequencyinduction coil (21) of said high-frequency induction heating device(20), said separating mechanism (25), which is located at a certainposition reached immediately after a heating process separating saidcoating resin (3) from said steel pipe (2), said take-up device (30)taking up said steel pipe (2) in said running direction thereof and saidrecovering device (40) recovering said separated steel pipe (2) andcoating resin (3), is characterized in that

a cutting means located at a position before said high-frequencyinduction coil (21) makes incision lines (18) in said coating resin (3)that reach in depth from a surface of said coating resin (3) to saidsurface of said steel pipe (2) and extend throughout a length of saidresin-coated pipe (1) at positions that divide a periphery of saidcoating resin (3) into at least two parts, that

by means of high-frequency induction heating, said steel pipe (2) isheated in such a manner that, when it reaches said separating mechanism(25) located at an appropriate position arrived at immediately after aheating process, a bottom layer of said coating resin (3) adjacent to aboundary of said steel pipe (2) reaches a condition separable from saidsteel pipe (2), that

said separating mechanism (25) separates said coating resin (3) fromsaid steel pipe (2) and severs said coating resin (3) along saidincision lines (18) and away from said steel pipe (2) into at least twopieces and then guides severed pieces of said coating resin (3) in saidrunning direction thereof, and that

said recovering device (40) recovers said resin pieces (3′) by smashingsaid resin pieces that are crushed flat in prescribed processes,including a taking-up process by said take-up device (30).

The invention as recited in Claim 3 relates to a method to separate andrecover steel pipe and coating resin from resin-coated steel pipe,intended to process a resin-coated steel pipe (1) which consists ofsteel pipe (2) and coating resin (3) adhered to an outer surface of saidpipe, employing a separating and recovering apparatus having a feedingdevice (10), a high-frequency induction heating device (20), aseparating mechanism (25), a take-up device (30) and a recovering device(40), said feeding device (10) feeding said resin-coated steel pipe (1)of certain length in a running direction thereof thereby passing andheating said resin-coated steel pipe (1) inside or near a high-frequencyinduction coil (21) of said high-frequency induction heating device(20), said separating mechanism (25), which is located at a certainposition reached immediately after a heating process, separating saidcoating resin (3) from said steel pipe (2), said take-up device (30)taking up said steel pipe (2) in said running direction thereof and saidrecovering device (40) recovering separated steel pipe (2) and coatingresin (3), is characterized in that

a cutting means located at a position before said high-frequencyinduction coil (21) makes incision lines (18) in said coating resin (3)that reach in depth from a surface of said coating resin (3) to saidsurface of said steel pipe (2) and extend throughout a length of saidresin-coated pipe (1) at positions that divide a periphery of saidcoating resin (3) into at least two parts, that

by means of high-frequency induction heating, said steel pipe (2) isheated in such a manner that, when it reaches said separating mechanism(25) located at an appropriate position arrived at immediately after aheating process, a bottom layer of said coating resin (3) adjacent to aboundary of said steel pipe (2) reaches a condition separable from saidsteel pipe (2), that

said separating mechanism (25) separates said coating resin (3) fromsaid steel pipe (2) and severs said coating resin (3) along saidincision lines (18) and away from said steel pipe (2) into at least twopieces and then guides severed pieces of said coating resin (3) in saidrunning direction thereof, and that

said recovering device (40) recovers said steel pipe (2) after crushingit into a flat condition but maintaining an original length thereof.

In the method to separate and recover steel pipe and coating resin fromresin-coated steel pipe according to any of Claim 1–3, the inventionrecited in Claim 4 is characterized in that

by means of high-frequency induction heating, said steel pipe (2) isheated in such a manner that, when it reaches said separating mechanism(25) located at an appropriate position arrived at immediately after aheating process, said layer of said coating resin (3) adjacent to saidboundary of said steel pipe (2) reaches a condition separable from saidsteel pipe (2), but at least said exterior side of said outer layer ofsaid coating resin (3) is kept under a temperature at which softeningoccurs.

In the method to separate and recover steel pipe and coating resin fromresin-coated steel pipe according to any of Claim 1–4, the inventionrecited in Claim 5 is characterized in that

said feeding device (10) is constructed as a feeding roll device (10)consisting of two or more sets of feeding rolls (11,12,13), each of saidsets of feeding rolls having a plurality of division rolls (11 a•11 b,12a•12 b,13 a•13 b), that

said feeding roll device (10) has a construction such that a prescribeddivision roll is given pressing force against said outer periphery ofsaid resin-coated steel pipe (1) toward an axis of said resin-coatedsteel pipe (1), and a groove formed on a periphery of each of saiddivision rolls engages with said outer periphery of said resin-coatedsteel pipe (1) and rotates to thereby feed said resin-coated steel pipe(1) in said running direction thereof, that

in said set of feeding rolls of said feeding device (10), which havesaid division roll that is given pressing force against said outerperiphery of said resin-coated steel pipe (1) toward said axis thereofand which are arranged to clamp said resin-coated steel pipe (1), at abottom of grooves of at least two of said division rolls, are providedthroughout periphery incision blades (17) of which tips (17 a) areprotruding, that

said tip (17 a) of said incision blade (17) protrudes from said bottomof said groove by a height no less than a thickness of said coatingresin (3), and that

as said feeding device (10) feeds said resin-coated steel pipe (1) insaid running direction thereof, said incision blades (17) that areforced against said resin-coated steel pipe (1) make incision lines(18).

In the method to separate and recover steel pipe and coating resin fromresin-coated steel pipe according to any of Claim 5, the inventionrecited in Claim 6 is characterized in that

said incision blades (17) are provided in said set of feeding rolls,which includes said division roll (13 b) that is given a force towardsaid axis of said resin-coated steel pipe (1) and is located on a sideof said high-frequency induction coil (21).

In the method to separate and recover steel pipe and coating resin fromresin-coated steel pipe according to Claim 5 or Claim 6, the inventionrecited in Claim 7 is characterized in that

an edge angle of said incision blades (17) is about 30 degrees or less.

In the method to separate and recover steel pipe and coating resin fromresin-coated steel pipe according to any of Claim 1–4, the inventionrecited in Claim 8 is characterized in that

said resin-coated steel pipe (1) is given two incision lines (18), that

said take-up device is constructed as a take-up roll device (30′) thatconsists of two or more sets of take-up rolls of which one has astake-up rolls two division rolls which are arranged opposing each otherprecisely on said incision lines (18,18) to clamp said steel pipe, that

said take-up roll device (30′) has a construction such that saidprescribed division roll is given pressing force against said outerperiphery of said steel pipe (2) toward said axis of said resin-coatedsteel pipe, and said periphery of each of said division rolls therebyengages with said outer periphery of said steel pipe (2) and rotates totake up said steel pipe (2) in said running direction thereof, that

a separating mechanism (115) comprises, in said take-up roll device(30′), a set of take-up rolls which, including a division roll (116a,116 b) given pressing force toward said axis of said steel pipe (2),are positioned on a side of said high-frequency induction coil (21) andwhich are either formed or not on a periphery with grooves (116 c) ofdepth about ⅓ to ¼ of a radius of said steel pipe (2) or less, and a runguide (117) provided at a distance from said steel pipe (2) to enclosesaid steel pipe (2) and that

in said take-up roll device (30′), when, on two division rolls (116a,116 b) in said set of take-up rolls that is positioned on said side ofsaid high-frequency induction coil (21), portions of said peripherygrooves (116 c•116 c) or said periphery surfaces facing saidhigh-frequency induction coil (21) come in touch with said incisionlines (18•18) in said coating resin (3) of said moving resin-coatedsteel pipe (1), through forces given to said two incision lines (18•18),said coating resin (3) is, starting at a fore end thereof, separatedfrom said steel pipe (2) and severed along said incision lines (18) andaway from said steel pipe (2) into two pieces and then guided by saidrun guide (117) in said running direction thereof.

In the method to separate and recover steel pipe and coating resin fromresin-coated steel pipe according to any of Claim 1–4, the inventionrecited in Claim 9 is characterized in that

said separating mechanism (25) is provided between said high-frequencyinduction coil (21) and said take-up device (30), that

said separating mechanism (25) comprises said dividing blades (26 b•26b) fixed at positions corresponding to said incision lines (18•18) whichdivide said coating resin (3) circumferentially into at least two partsin such a manner that pointed tips of said dividing blades oppose saidincision lines (18•18) in said coating resin (3) of said resin-coatedsteel pipe (1), which comes moving in a running direction thereof andsaid run guide (27) located at a distance from said steel pipe (2) toenclose said steel pipe (2), that

as said pointed ends of said dividing blades (26 b•26 b) strike againstsaid incision lines (18•18) made in said coating resin (3) of saidresin-coated steel pipe (1) moving in said running direction, saidcoating resin (3) is, from said fore end thereof, separated from saidsteel pipe (2) along said incision lines (18•18) and away from saidsteel pipe (2), and severed into at least two pieces which are guided bysaid run guide (27) in said running direction thereof.

In the method to separate and recover steel pipe and coating resin fromresin-coated steel pipe according to any of Claim 1–4, the inventionrecited in Claim 10 is characterized in that

said separating mechanism (75) is provided between said high-frequencyinduction coil (21) and said take-up device, that

said separating mechanism (75) comprises a set of severing rolls (76 c)consisting of two division rolls (76 d•76 d) that are arranged to opposeeach other at positions corresponding to said incision lines (18•18) toclamp said resin-coated steel pipe (1) and a run guide (27) that isprovided at a distance from said steel pipe (2) to enclose said steelpipe (2), and that

in said set of severing rolls (76 c), at least one division roll isgiven a force against said outer surface of said steel pipe (2) towardsaid axis thereof and said two division rolls (76 d•76 d) rotate with aperiphery thereof engaging with said outer surface of said steel pipe(2), that

said periphery of each of said two division rolls (76 d•76 d) is formedinto a shape selected as a preferred one for said separating mechanism(75), and that

in said set of severing rolls (76 c), when portions of said peripherysurfaces facing said high-frequency induction coil (21) come in touchwith said incision lines (18•18) in said coating resin (3) of saidmoving resin-coated steel pipe (1), through force given to said twoincision lines (18•18), said coating resin (3) is, starting at said foreend thereof, separated from said steel pipe (2) and severed along saidincision lines (18) and away from said steel pipe (2) into two pieces,which are then guided by said run guide (27) in said running directionthereof.

In the method to separate and recover steel pipe and coating resin fromresin-coated steel pipe according to any of Claim 1–4, the inventionrecited in Claim 11 is characterized in that

said separating mechanism (105) is provided between said high-frequencyinduction coil (21) and said take-up device, that

said separating mechanism (105) comprises a sucking device (106) thathas a plurality of sucking surfaces (106 b) which, surrounding saidresin-coated steel pipe (1), attract an outer surface of said coatingresin (3) and a run guide (107) provided at a distance from said steelpipe (2) enclosing said pipe (2), that

said plurality of sucking surfaces (106 b) diverge in distancetherebetween in a direction from said high-frequency induction coil (21)to said take-up device to pull away said coating resin (3) from saidsteel pipe (2), that

as said resin-coated steel pipe (1) which has said coating resin (3)divided into at least two parts moves through said plurality of suckingsurfaces (106 b) of said sucking device (106), said sucking device (106)attracts each piece of said coating resin (3) and, thereby separatingsaid coating resin (3), starting at said fore end thereof, from saidsteel pipe (2), sever said coating resin (3) along said incision lines(18) and away from said steel pipe (2) into at least two pieces, whichare guided in said running direction thereof by said run guide (107).

In the method to separate and recover steel pipe and coating resin fromresin-coated steel pipe according to any of Claim 1–4, the inventionrecited in Claim 12 is characterized in that

said resin-coated steel pipe (1) is given two incision lines (18) at anupper and lower positions, that

said separating mechanism (25) is provided with a run guide consistingof right and left guide pieces (27 a•27 a) located on either side ofsaid steel pipe (2) and a lower piece (27 b) located below said pipe (2)at a distance from said pipe (2) to avoid interference with saidseparating mechanism (25), and that

said separating mechanism (25) separates said coating resin (3),starting at said fore end thereof, from said steel pipe (2) and seversaid coating resin (3) along said incision lines (18) and away from saidpipe (2) into left and right pieces which are guided by said run guidein said running direction thereof.

The invention as recited in Claim 13 relates to an apparatus to separateand recover steel pipe and coating resin from resin-coated steel pipe,intended to process a resin-coated steel pipe (1) which consists ofsteel pipe (2) and coating resin (3) adhered to an outer surface of saidpipe (2), comprising a feeding device (10) which feeds said resin-coatedsteel pipe (1) of any length in a running direction thereof, ahigh-frequency induction heating device (20) which heats saidresin-coated steel pipe (1) passing inside or near a high-frequencyinduction coil (21), a separating mechanism (25) which, provided at anappropriate position reached by said moving resin-coated steel pipe (1)immediately after passing an induction coil (21), separates said coatingresin (3) from said steel pipe (2), a take-up device and a recoveringdevice (40) which recovers steel pipe (2) and coating resin (3) insegregated condition, is characterized in that

a means is provided at a position before said high-frequency inductioncoil (21) to make incision lines (18) in a surface of said resin-coatedsteel pipe (1) at locations for division into at least two pieces insuch a manner that said incision lines (18) reach in depth from saidsurface of said coating resin (3) to said surface of said steel pipe(2), that

said high-frequency induction heating device (20) is capable of heatingsaid steel pipe (2) by means of high-frequency induction into acondition such that, at a position of said separating mechanism (25), abottom layer of said coating resin (3) adjacent to a boundary of saidsteel pipe (2) is separable from said steel pipe (2), and that

said separating mechanism (25) is constructed in such a manner as to beable to separate said coating resin (3), starting at a fore end thereof,from said steel pipe (2) and sever said coating resin along saidincision lines (18) and away from said steel pipe (2) into at least twopieces.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a front view of the first embodiment of the apparatus toseparate and recover steel pipe and coating resin from resin-coatedsteel pipe according to the present invention;

FIG. 2 is a plan view of the separating and recovering apparatus of FIG.1;

FIG. 3 is an enlarged front view of the main part and the coupling partbetween the main part and the steel pipe recovering part of theseparating and recovering apparatus of FIG. 1;

FIG. 4 is a plan view of the main part and the coupling part of FIG. 3;

FIG. 5 is a right side view of the main part of FIG. 3;

FIG. 6 is an enlarged front view of the feeding roll device of FIG. 3;

FIG. 7 is a plan view of the feeding roll device of FIG. 6;

FIG. 8 is a sectional view taken at A—A line of FIG. 6;

FIG. 9 is an enlarged view of D part of FIG. 8;

FIG. 10 is an enlarged front view of the separating mechanism of FIG. 3;

FIG. 11 is a plan view of the separating mechanism of FIG. 10;

FIG. 12 is a right side view of the separating mechanism of FIG. 10;

FIG. 13 is an enlarged view of E part of FIG. 12;

FIG. 14 is a sectional view taken at B—B line of FIG. 3;

FIG. 15 is an enlarged view of F part of FIG. 14;

FIG. 16 is a sectional view taken at C—C line of FIG. 3;

FIG. 17 is an enlarged view of G part of FIG. 16;

FIG. 18 is an enlarged front view of the part of FIG. 1 ranging from thesteel pipe recovering part through the front part of the smashingdevice;

FIG. 19 is a plan view of the part shown in FIG. 18;

FIG. 20 is a right side view of the front central part of the steel piperecovering part shown in FIG. 18;

FIG. 21 is a front view of the second embodiment of the apparatus toseparate and recover steel pipe and coating resin from resin-coatedsteel pipe according to the present invention;

FIG. 22 is a plan view of the separating and recovering apparatus ofFIG. 21;

FIG. 23 is an enlarged front view of the main part and the coupling partbetween the main part and the steel pipe recovering part of theseparating and recovering apparatus of FIG. 21;

FIG. 24 is a plan view of the main part and the coupling part of FIG.23;

FIG. 25 is a right side view of the main part of FIG. 3;

FIG. 26 is an enlarged front view of the feeding device of FIG. 23;

FIG. 27 is a plan view of the feeding device of FIG. 26;

FIG. 28 is a sectional view taken at H—H line of FIG. 26;

FIG. 29 is an enlarged front view of the separating mechanism of FIG.23;

FIG. 30 is a plan view of the separating mechanism of FIG. 29;

FIG. 31 is a right side view of the separating mechanism of FIG. 29;

FIG. 32 is an enlarged view of J part of FIG. 31;

FIG. 33 is a view showing another embodiment of the division rolls ofFIGS. 30–32;

FIG. 34 is a sectional view taken at I—I line of FIG. 23;

FIG. 35 is an enlarged view of K part of FIG. 34;

FIG. 36 is an enlarged view of M part of FIG. 23;

FIG. 37 is an enlarged front view of the steel pipe recovering part ofthe separating and recovering apparatus of FIG. 21;

FIG. 38 is a plan view of the steel pipe recovering part of FIG. 37;

FIG. 39 is a right side view of the front central part of the steel piperecovering part shown in FIG. 37;

FIG. 40 is a front view of the third embodiment of the separatingmechanism;

FIG. 41 is a plan view of the separating mechanism of FIG. 40;

FIG. 42 is a right side view of the separating mechanism of FIG. 40;

FIG. 43 is a front view of the fourth embodiment of the separatingmechanism showing the device at the center and portions of the apparatusin front of and behind the device in the running direction of the steelpipe;

FIG. 44 is an enlarged front view of the separating mechanism of FIG.43;

FIG. 45 is a plan view of the separating mechanism of FIG. 44;

FIG. 46 is a right side view of the separating mechanism of FIG. 44;

FIG. 47 is a side elevational view of the fifth embodiment of theseparating mechanism; and

FIG. 48 is a diagonal view showing a resin-coated steel pipe with aportion broken away.

THE MOST PREFERRED EMBODIMENT OF THE INVENTION

FIGS. 1 and 2 are a front and a plan view showing the whole of the firstembodiment of the separating and recovering apparatus to practice themethod to separate and recover steel pipe and coating resin fromresin-coated steel pipe stated in Claim 1, and FIG. 48 shows aresin-coated steel pipe 1 processed pursuant to the first embodiment ofthe separating and recovering apparatus.

The resin-coated steel pipe 1 shown in FIG. 1 consists of an adhesionlayer a made by spreading an adhesive on the outer surface of steel pipe2 and coating resin 3 of uniform thickness made of AAS resin or ABSresin coating over the adhesion layer. On the inner surface of the steelpipe is painted an antirust paint as a thin film to form an antirustlayer b.

In FIGS. 1 and 2, from back to fore in the running direction of theresin-coated steel pipe 1 or the steel pipe 2, numeral 5 designates afeeder support, 6 designates a main part support, 7 a coupling partsupport, 8 a steel pipe recovering part support, and 9 designates asmasher support.

Casters (not designated by symbols) can be provided on the feet of eachof the supports 5,6,7,8,9, to facilitate operations such as moving,shipping, carrying, and installing. Further, the supports 5,6,7,8,9 arealigned to form a straight run course for the resin-coated steel pipe 1or the steel pipe 2 and each adjacent pair thereof is connected withappropriate connections 100 a,100 b (FIG. 1–4).

As shown in FIGS. 1 and 2, on the feeder support 5 of the supports5,6,7,8,9, a plurality of feeding rolls 5 a are provided in series inthe running direction of the resin-coated steel pipe 1 to supply theresin-coated steel pipe of an arbitrary length to the run course thereofand for the purpose guide the resin-coated steel pipe 1 straight in thedirection of the axis thereof.

On the main part support 6 are provided, from back to fore in therunning direction of the resin-coated steel pipe 1 or the steel pipe 2,a feeding roll device 10 (having a means to make incision lines) to feedthe resin-coated steel pipe 1 of an arbitrary length in the runningdirection thereof, a high-frequency induction heating device that heatsthe resin-coated steel pipe 1 as the pipe passes inside or near ahigh-frequency induction coil 21, a separating mechanism 25 (including afirst run guide 27 as the rear part of the run guide; see FIGS. 10–12),which, provided at an appropriate position reached immediately afterpassing the high-frequency induction coil 21, separates the coatingresin 3 from the steel pipe 2 and severs the coating resin 3, a take-uproll device 30 (including take-up rolls 33 that crush flat the coatingresin 3; see FIGS. 13–15), which takes up the steel pipe 2, and a secondrun guide 34, which, as the fore part of the run guide, guides theflattened coating resin 3′ (see FIGS. 3,4,14 and 15).

A first roller conveyer 41, and ahead of the conveyer 41, a crushingdevice to crush the steel pipe 2 having three sets of crushing rolls43,44 and 45 (see FIGS. 16 and 17) are provided on the coupling partsupport 7.

A second roller conveyer 46 at an intermediate height, a trolley 47 forrecovering steel pipe at a lower position and a belt conveyer 48 at ahigher position are provided on the steel pipe recovering part support8.

A smasher 49 is mounted at a lower position of the smasher support 9.

The recovering device 40 comprises the coupling part support 7, thesteel pipe recovering support 8, the smasher support 9 and the devicesand members provided on the supports 7,8,9, and serves the purpose torecover the separated steel pipe 2 and the coating resin 3 in asegregated condition.

This separating and recovering apparatus is provided with a cuttingmeans (consisting of, for example, division rolls 13 a,13 a and incisionblades 17,17 in the feeding roll device 10; see FIGS. 6–9) located at aposition reached before the high-frequency induction coil 21 is passedto make incision lines 18 (see FIGS. 7,9 and 11) in the coating resin 3that reach in depth from the surface of the coating resin 3 to thesurface of the pipe 2 and extends throughout the length of the pipe 1 atupper and lower locations on the periphery of the coating resin 3thereby to divide the coating resin 3 into two pieces.

The number and locations of the incision lines 18 are not limited to twoor to upper and lower positions.

The high-frequency induction heating device 20 can heat throughhigh-frequency induction heating the steel pipe 2 to a condition that,at the separating mechanism 25, the boundary part of the coating resin 3is ready to be separated from the steel pipe 2.

The separating mechanism 25 has a construction that enables it toseparate the coating resin 3, starting at the fore end thereof, from thesteel pipe 3, and sever the coating resin 3 along the incision lines 18and away from the steel pipe 2 into two right and left pieces (theinvention stated in Claim 13).

Each of the severed pieces of the coating resin 3 is guided in therunning direction of the pipe by the run guide (the first run guide 27which, as the rear part of the run guide, severs to guide the coatingresin 3 separated from the steel pipe 2 and severed).

The steel pipe 2′ and the coating resin 3′ are flattened afterseparation and are recovered in a segregated condition by the recoveringdevice 40.

The separating and recovering apparatus first makes incision lines 18 inthe coating resin 3 that reach in depth from the surface of the coatingresin 3 to the surface of the pipe 2 and extends throughout the lengthof the pipe 1 at upper and lower locations on the periphery of thecoating resin 3 by means of a cutting means located at a positionreached before the high-frequency induction coil 21 is passed, andthereby divides the coating resin 3 into two right and left pieces.

Then, the separating and recovering apparatus heats throughhigh-frequency induction heating the steel pipe 2 to a condition that,at the separating mechanism 25 provided at a position reachedimmediately after passing the high-frequency induction coil 21, theboundary part of the coating resin 3 is ready for separation from thesteel pipe 2.

Next, by means of the separating mechanism 25, the separating andrecovering apparatus separates the coating resin 3 from the steel pipe 2and severs the coating resin 3 along the incision lines 18 and away fromthe steel pipe 2 and severs the coating resin 3 along the incision lines18 and away from the steel pipe 2 into at least two pieces (theinvention stated in Claim 1).

The run guide 27 guides the severed pieces of the coating resin 3 in therunning direction of the pipe.

Then, the recovering device 40 recovers in segregated condition thesteel pipe 2′ and the coating resin pieces 3′, both of which areflattened after separation.

FIGS. 3 through 20 show the first embodiment of the separating andrecovering apparatus.

As for example, the resin-coated steel pipe 1 has an outer diameter of27.7 mm; the steel pipe 2 is of SPCC (JIS G 3141 cold rolled steel plateand sheet; for general use); the steel pipe 2 is 25.5 mm in outerdiameter and 0.7 mm in thickness; the material of the coating resin 3 isAAS or ABS having a melting temperature of 160° C.–200° C. and thethickness is 1.1 mm; the thickness of the acrylic rubber adhesive as theadhesion layer a is 0.02 mm–0.03 mm; the softening temperature of AAS orABS resin is 120° C.–140° C. and the melting temperature of the adhesiveis 150° C.–160° C.

With the conditions stated above, the running speed of the resin-coatedsteel pipe 1 moved by the feeding roll device 10 and the take-up rolldevice 30 is set to about 10 m/minute.

The running speed of 10 m/minute means that, using the separating andrecovering apparatus described in detail in the following, theresin-coated steel pipe 1 will be, when arriving at the separatingmechanism 25, in such conditions that due to the high-frequencyinduction heating the adhesive is kept in a melted state while the outerlayer of the coating resin 3 separated from the steel pipe 2 and severedis not softened, with a surface temperature of 50° C.–60° C., which isnearer to normal temperature than softening temperature, maintaining therigidity sufficient to remain solid.

In other words, with this running speed, the coating resin 3 can attainthe preferred condition in which the layer of the coating resin 3adjacent to the boundary of the steel pipe 2 has, at the separatingmechanism 25, a temperature high enough to allow it to be separable fromthe steel pipe, while at least the outer layer part of the coating resin3 is kept at a temperature lower than necessary for softening (theinvention stated in Claim 4).

Owing to the fact described above, the pieces of the coating resin 3 areleft with sufficient rigidity and easily guided in the determineddirection by the guide in the processes beginning with the separatingmechanism 25, and can be easily recovered. With reference mainly toFIGS. 6–9, the first feeding device provided in the running course ofthe resin-coated steel pipe 1 is described below.

The feeding device is shown as the feeding roll device 10 having threesets of feeding rolls 11,12,13, which, arranged in series in the runningdirection of the resin-coated steel pipe 1, consist of pairs of divisionrolls 11 a•11 b, 12 a•12 b and 13 a•13 b, respectively provided at upperand lower points opposing each other to clamp the resin-coated steelpipe 1.

The feeding roll device 10 has a force-adjusting mechanism 16 to imposeforce on a prescribed division roll against the outer surface of theresin-coated steel pipe 1 toward the axis thereof and the groove formedon the periphery of each of the division rolls 11 a•11 b,12 a•12 b,13a•13 b engages with the outer surface of the resin-coated steel pipe 1for rotation and thereby feed the resin-coated steel pipe 1.

As a means to make incision lines, in the feeding roll device 10, theset of feeding rolls, including the roll that is given pressing forcetoward the axis of the resin-coated steel pipe 1, is provided withincision blades 17 at the bottom of the grooves of the rolls located atthe upper and lower positions opposing each other, in such a manner asto protrude from the bottom by a height no less than the thickness ofthe coating resin 3.

As the feeding roll device 10 feeds the resin-coated steel pipe 1 in therunning direction thereof, the incision blades 17 make incision lines 18using the pressing force provided, (see FIGS. 6,8 and 9).

The number of sets of the feeding rolls is, however, not limited tothree but can be two or four, or more. Moreover, the arrangement andnumber of the division rolls are not limited to only the upper and lowerlocation and two rolls. And accordingly the arrangement and number ofthe incision lines are not limited to the upper and lower locations andtwo lines. Further, the number of the sets of feeding rolls includingthe roll given the pressing force toward the axis of the resin-coatedsteel pipe 1 is not limited to three.

In any event, the incision blades 17 as the means to make incision lines18 are incorporated in one set of the feeding rolls, (in accordance withthe invention stated in Claim 5).

The incision blades 17 are preferably provided in the set of rolls 13that includes the division roll 13 b, which is given the pressing forcetoward the axis of the resin-coated steel pipe 1 and is positioned onthe side of the high-frequency induction coil 21, (see FIGS. 6,8 and 9;the invention stated in Claim 6).

The incision blades 17 preferably have an edge angle of about 30 degreesor less, (see FIG. 9; the invention stated in Claim 7).

The embodiment of the feeding roll device 10 is described below indetail with reference to FIG. 6.

The feeding roll device 10 comprises a fixed block 14, which is fixed onthe main part support 6, a movable block 15, which is provided above thefixed block 14 and is vertically movable, and three sets of feedingrolls 11,12,13. The three sets of the feeding rolls 11,12,13 have twodivision rolls 11 a•11 b,12 a•12 b,13 a•13 b, respectively, as a set ofthe feeding rolls located at the upper and lower positions opposing eachother to clamp the resin-coated steel pipe 1, and the lower rolls 11a,12 a,13 a are incorporated in the fixed block 14 while the upper rolls11 b,12 b,13 b are incorporated in the movable block 15. On theperiphery of each of the division rolls 11 a•11 b, 12 a•12 b, 13 a•13 bis formed a groove 11 c or 12 c or 13 c having the same curvature as theouter periphery of the resin-coated steel pipe 1.

A force-adjusting mechanism 16 is incorporated in the combination of thefixed block 14 and the movable block 15.

This force-adjusting mechanism 16 serves the purpose of feeding theresin-coated steel pipe 1 in the running direction thereof and makingthe incision lines 18 by giving a constant and strong force on each ofthe division rolls 11 b,12 b,13 b incorporated in the movable block 15,in order to have them pressed firmly against the surface of theresin-coated steel pipe 1, even when the resin-coated steel pipe 1 haslocal uneven portions on the surface, partial losses of the coatingresin 3 or foreign substances stuck thereon.

For this purpose, four gears 10 c,10 d,10 j and 10 k are incorporated inthe feeding roll device 10 to transmit the torque from a motor 10 m tothe two division rolls 11 b,13 b, (see FIGS. 6–8; in the take-up rolldevice 30 to take up the steel pipe 2, gears are not necessarily needed;also the compression coil spring 16 b is not required to be as strong asin the feeding roll device 10).

On the fixed block 14, vertical axles 16 a•16 a, which have a greaterdiameter at the bases 16 a′•16 a′ thereof, are provided and the axles 16a•16 a protrude above the upper surface of the movable block 15.Compression coil springs 16 b•16 b are placed on the upper half portionsof the axles 16 a•16 a and on the upper surface of the movable block 15,and on each of the springs 16 b•16 b is placed a push plate 16 c. Afixed plate 16 d is provided on the upper end surfaces of the verticalaxles 16 a•16 a and secured to the upper end surfaces of the verticalaxles 16 a•16 a by means of bolts.

At the center of the push plate 16 c, a force-adjusting bolt 16 f,capable of rotating relative to the push plate 16 c, stands and extendsthrough the fixed plate 16 d in such a way that the upper half of theforce-adjusting bolt 16 f protrudes above the fixed plate 16 d. On theupper surface of the fixed plate 16 d, a female screw plate 16 e isscrewed on the upper half of the force-adjusting bolt 16 f and is bolteddown to the fixed plate 16 b. On the female screw plate 16 e is screweda lock nut 16 g.

The way in which the lower surface of the movable block 15 is pressedagainst the upper surfaces of the bases 16 a′•16 a′ of the verticalaxles 16 a•16 a, determines the limit of advance (the lower limit) ofthe division rolls 11 b,12 b,13 b incorporated in the movable block 15.

At the limit position of advance of each of the division rolls 11 b,12b,13 b, the bottom of each of the periphery grooves 11 c,12 c,13 c ofthe division rolls 11 b,12 b,13 b is set to protrude in the directiontoward the axis of the resin-coated steel pipe 1 by a quantity greaterthan the thickness of the coating resin 3, 1.5–2.0 mm, for example, fromthe surface of the moving resin-coated steel pipe 1 to cope with thecase of a partial loss of the coating resin 3, (see the symbol D1 inFIGS. 8 and 9).

With the above force-adjusting mechanism 16, the force-adjusting bolts16 f•16 f are raised or lowered to adjust compression of the compressioncoil springs 16 b•16 b and, through adjustment of the force given toeach of the division rolls 11 b,12 b,13 b incorporated in the movableblock 15, the desired force (the symbol F in FIGS. 8 and 9) exerted bythe division rolls 11 b,12 b,13 b against the surface of theresin-coated steel pipe 1 toward the axis is obtained. Then, by firmlytightening the lock nut 16 g on the force-adjusting bolt 16, the degreeof the pressing force F can be fixed.

The division rolls 11 a,12 a,13 a incorporated in the fixed block 14exert force F′ of the same magnitude as F, that is, the reaction forceof F, against the resin-coated steel pipe 1 toward the axis thereof.

The mechanism to give force to the prescribed division rolls is notlimited to that shown in the drawings, and other compositions, such asusing, for example, tension coil springs instead of the compression coilsprings 16 b•16 b is also possible.

The incision blades 17•17 as a means to make incision lines aredescribed below.

In on set of the three feeding rolls 11,12,13, preferably in the thirdset, that is, the feeding rolls 13 located on the side of thehigh-frequency induction coil, incision blades 17•17 as a means to makeincision lines are provided at the center of the bottom of the peripherygrooves 13 c•13 c of the two division rolls 13 a, 13 b located at theupper and lower positions opposing each other, each forming a ringsandwiched by the right and left portions 13 a′•13 a″, 13 b′•13 b″ ofthe rolls 13 a•13 b in such a manner that the blade edge 17 a of each ofthe incision blades 17•17 protrudes from the bottom of the peripherygroove 13 c by a height no less than the thickness of the coating resin3. The incision blades 17•17 are formed so as to have an edge 17 a withan edge angle not greater than about 30 degrees, (see in FIGS. 6,8 and 9and the symbol θ1 in FIG. 9).

According to the construction of the feeding roll device 10 describedabove, at the position before passing the high-frequency induction coil21, the incision blades 17•17, which are already given forces F and F″from at least two division rolls 13 a•13 b, can make the incision lines18 that reach in depth from the surface of the coating resin 3 to thesurface of the steel pipe 2 and thereby divide the coating resin 3precisely into two, right and left (circumferential) pieces.

Hence, the divided coating resin 3 can be kept securely in the state ofbeing divided into right and left pieces after passing thehigh-frequency induction coil 21, (in accordance with the inventionstated in Claim 5).

The incision blades 17, as a means to make incision lines, are providedin a set of feeding rolls of the feeding roll device 10. Owing to this,the apparatus can avoid becoming bulky and the manufacturing cost canthereby be saved, (in accordance with the invention stated in Claim 5).

Further, the feeding roll device 10 consists of three sets of feedingrolls 11,12 and 13, and the incision blades 17•17 are provided on theset of feeding rolls 13 located on the side of the high-frequencyinduction coil 21 having the division rolls 13 a•13 b given the forcesF,F′ toward the axis of the resin-coated steel pipe 1, (see FIGS. 6,8,and 9).

Owing to this arrangement, the incision blades 17•17 can make theincision lines 18 while the resin-coated steel pipe 1 is moving stablysupported by the rear two sets of the feeding rolls 11 and 12, whichmeans that the operation of making the incision lines 18 itself isaccomplished in a stable fashion, (in accordance with the inventionstated in Claim 6).

The edge angle of the edges 17 a•17 a of the incision blades 17•17 isnot greater than 30 degrees. The edges 17 a•17 a of the incision blades17•17, therefore, neatly cut the coating resin 3 into two pieces withoutsquashing the lines of incision, (see FIG. 9; the invention stated inClaim 7).

In FIGS. 5,6 and 7, symbols 10 a and 10 b designate a motor and a shaftrespectively, 10 c•10 d designate gears, 10 e•10 f are timing pulleys,10 g is a timing belt, 10 j•10 k also designate gears and 10 m is asafety cover.

The high-frequency induction heating device 20 and the high-frequencyinduction coil 21 are almost the same as described in the explanation ofthe previous art and the description thereof is omitted herein.

However, it should be noted that in the resin-coated steel pipe 1, thesteel pipe 2 is heated by means of high-frequency induction heating tosuch a condition that when the steel pipe 2 reaches the separatingmechanism 25 located at an appropriate position arrived at immediatelyafter heating process, the boundary layer of the coating resin 3 reachesa separable condition from the steel pipe 2, while the outer layer ofthe coating resin 3, at least the outer half thereof, is kept under thesoftening temperature, (according to the invention of Claim 4).

The separating mechanism 25 is described below with reference to FIGS.10–13.

The separating mechanism 25 is provided independently between thehigh-frequency induction coil 21 and the take-up roll device 30.

The separating mechanism 25 comprises the dividing blades 26 b•26 bfixed at the upper and lower positions at which the coating resin 3 isdivided in such a manner that the pointed tips of the dividing blades 26b,26 b oppose the incision lines 18•18 in the coating resin 3 of theresin-coated steel pipe 1 moving in the running direction thereof andthe first run guide 27 (the rear part of the run guide) provided at adistance from and enclosing the resin-coated steel pipe 1.

By applying the pointed edges of the dividing blades 26 b•26 b againstthe incision lines 18•18 in the coating resin 3 of the resin-coatedsteel pipe 1 moving in the running direction thereof, the separatingmechanism 25 separates the coating resin 3, starting from the fore endthereof, from the steel pipe 2 and severs the resin 3 along the incisionlines 18•18 and away from the resin-coated steel pipe 1 into two, rightand left pieces which are guided by the run guide 27 in the runningdirection of thereof.

The arrangement and number of the incision lines 18•18 and the dividingblades 26 b•26 b are, however, not limited to the upper and lowerpositions or to only two (the invention stated in Claim 9).

An embodiment of the separating mechanism 25 is described below indetail with reference to FIGS. 6–9.

The separating mechanism 25 described above comprises the dividingblades 26 b•26 b and the first run guide 27. In the event the dividingblades 26 b•26 b are provided, on the main body 26 fixed on the mainpart support 6 are mounted adjustable angle axles 26 a•26 a to bevertically adjustable, and respectively support the dividing blades 26b•26 b arranged at the upper and lower positions opposing each other toclamp the resin-coated steel pipe 1. The upper and lower adjustableangle axles 26 a•26 a have the fore ends thereof protruding from theouter surface of the main body 26 to support the dividing blades 26 b•26b on the fore end surfaces thereof and have the rear ends recessed by asuitable dimension from the outer surface of the main body 26. On therear end surfaces of the adjustable angle axles 26 a•26 a are providedfit plates 26 c•26 c, and adjust bolts 26 d•26 d extend through the fitplates 26 c•26 c at the centers thereof to be screwed to the rear endsof the adjustable angle axles 26 a•26 a. Further, at the back of the fitplates 26 c•26 c, lock nuts 26 e•26 e are provided.

In the composition having the dividing blades 26 b•26 b described above,suitable positions of the dividing blades 26 b•26 b are first determinedby vertically advancing or retracting the adjust bolts 26 d•26 d andthrough the adjustable angle axles 26 a•26 a by adjusting the positionsof the dividing blades 26 b•26 b in the direction toward the axis of theresin-coated steel pipe 1. Then, the determined positions are fixed byfastening the lock nuts 26 e•26 e.

In this fixed condition, the pointed ends (θ2=90 degrees in FIG. 11) ofthe dividing blades 26 b•26 b are aligned to the incision lines 18•18 ofthe resin-coated steel pipe 1 moving in the running direction thereof.

The position of the pointed ends of the dividing blades 26 b•26 b in theaxial direction of the resin-coated steel pipe 1 is set in such a mannerthat when the thickness of the coating resin 3 is 1.1 mm (the symbol tin FIG. 13), the inner surface of each of the dividing blades 26 b•26 band the outer surface of the steel pipe has a clearance of 0.2 mm–0.3 mm(the symbol s in FIG. 13) in between.

The first run guide 27, enclosing the resin-coated steel pipe 1, extendsthe length between the position a little before the dividing blades 26b•26 b and the position ahead of the take-up roll device 30, arranged insuch a manner as not to interfere with the dividing blades 26 b•26 b andthe take-up rolls 31,32,33 of the take-up roll device 30 describedhereinafter (see FIGS. 3,4 and 12), and constituting the rear part ofthe run guide consisting of the side pieces 27 a•27 a on right and left,and a lower piece 27 b located at a distance from the resin-coated steelpipe 1 serves the purpose of guiding the pieces of the coating resin 3,which, given the incision lines 18•18 at the upper and lower position,is separated from the steel pipe 2 and severed by the dividing blades 26b•26 b with the right and left pieces 27 a•27 a and the lower piece 27 bin the running direction of the pieces of the coating resin 3.

The lower piece 27 b may have right and left portions integral with thecentral portion at the part where there is no fear of interference, (notshown; in FIGS. 4 and 11, the central portion is removed throughout thelength; according to the invention stated in Claim 12).

The symbol 27 c designates a base for mounting in the run guide 27.

According to the composition of the separating mechanism 25, there is nofear of cut off pieces of the steel pipe 2 getting into the separatedcoating resin 3 because separation is effected without a scrapingoperation of the dividing blades 26 b•26 b contacting the steel pipe 2.The pointed ends of the dividing blades 26 b•26 b hit against theincision lines 18•18 in the coating resin 3 of the resin-coated steelpipe 1 moving in the running direction thereof.

Owing to this, by the severing effect of the dividing blades 26 b•26 bfor the coating resin 3 cut by the incision lines 18•18 into two, rightand left pieces (cut into two parts along the circumference), as thepointed ends of the dividing blades 26 b•26 b hit against the incisionlines 18•18, the fore end of the pieces of the coating resin 3 split anddiverge to right and left, and are thereby separated from the steel pipe2 and severed along the incision lines 18•18 and away from the steelpipe 2 into two pieces. Then, each of the severed pieces of the coatingresin 3 is guided by the run guide 27 in the running direction thereof.Since the severed state and guiding is maintained, the coating resin 3is severed completely throughout the length thereof along the incisionlines 18•18 and away from the steel pipe 2 into two pieces.

The separating mechanism 25 is provided between the high-frequencyinduction coil 21 and the take-up roll device 30 as a take up meansindependently and exclusively for the separating operation, which meansthat the performance thereof as separating means can be furtherenhanced.

The embodiment of the take-up device 30 as a take up means is describedbelow using FIGS. 3,4,14 and 15.

As shown in FIGS. 3 and 4, the take-up roll device 30 comprises a fixedblock, a movable block and three sets of take-up rolls, and, since thecomposition by which each of the three sets of the take-up rollsconsists of two division rolls located at the upper and lower positionsopposing each other, by which the lower one is incorporated in the fixedblock and the upper one is incorporated in the movable block, and bywhich the mechanism to give pressing force is incorporated in thecombination of the fixed and the movable blocks are all the same as thefeeding roll device 10, and have the same effects, the devices andmembers having the same functions are given the same symbols and thedescription thereof is omitted.

In the take-up roll device 30 are incorporated three sets of take-uprolls 31,32 and 33, each consisting of two division rolls located at theupper and lower positions opposing each other, and at the center of eachof the division rolls is formed a peripheral groove having the samecurvature as the outer surface of the steel pipe 2.

Of the three sets of the take-up rolls 31,32 and 33, one, preferably thethird set of the take-up rolls, that is, the take-up rolls 33 on theside of the recovering device 40, has division rolls 33 a•33 b havinggreater width than the rolls in the sets 31 and 32 as shown in FIG. 4,the flat portions 33 d•33 d of the periphery surface on the both sidesof the groove 33 c being accordingly wider. And, as shown in FIGS. 14and 15, the outer diameters of the division rolls 33 a•33 b located atthe upper and lower positions are set so as to have a clearance inbetween as to be able to crush the right and left pieces of the coatingresin 3•3 into inwardly folded and flat condition.

The second run guide 34 (the fore part of the run guide), enclosing theresin-coated steel pipe 1, extends the length between the midpoint ofthe division rolls 33 a•33 b and the position ahead of the take-up rolldevice 30, comprises right and left pieces 34 a•34 a provided at adistance from resin-coated steel pipe 1 and a lower piece 34 b arrangedin such a manner as to avoid interference with the take-up roll device30, and is bent upward at the point slightly before the first rollerconveyer 41. The guide 34 is divided into the right and left parts bythe pieces 34 a•34 a on both sides and the lower piece 34 b, and guidesthe pieces of the coating resin 3 being crushed in the running directionthereof.

The symbol 34 c designates a base for mounting provided in the secondguide 34.

In the take-up roll device 30, therefore, as each of the division rollsrotates, the periphery grooves take up and feed forward the steel pipe2, while the flat periphery portions 33 d•33 d on the both side of thegroove 33 c take up and crush the right and left coating resin pieces3•3 that come running into folded and flat condition, and feed forwardthe processed resin pieces 3•3. The second run guide 34 guides thecoating resin pieces 3•3 in a rising pass.

With the take-up roll device 30 described above, the coating resin 3separated from the steel pipe 2 can be crushed flat.

The embodiment of the recovering device 40 is described below withreference to FIGS. 3,4, and 16–20.

Ahead of the main part support 6 the coupling part support 7 is providedas the first support in the recovering device 40.

As shown in FIGS. 3,4,16 and 17, on the coupling part support 7, in therunning direction of the steel pipe 2, the first roller conveyer 41 isprovided, which first receives the steel pipe 2 from the take-up rolldevice 30 and feeds forward the steel pipe 2, and following the conveyer41, the steel pipe crushing device 42 is provided, which crushes andfeeds forward the steel pipe 2.

In the steel pipe crushing device 42 are incorporated three sets ofcrushing rolls 43,44 and 45, each consisting of two division rollslocated at the upper and lower positions opposing each other, and on theperiphery of each roll of the rear two sets of crushing rolls 43,44formed a peripheral groove of appropriate shape. As shown in FIGS. 16and 17, the two division rolls 45 a•45 b of the fore set of crushingrolls 45 have flat peripheral surfaces without a groove and havediameters set in such a manner that the peripheral surfaces maintain aclearance in between which the steel pipe 2 moving in the runningdirection thereof can be crushed flat.

Therefore, as each of the division rolls rotates, the peripheral surfaceof the division rolls 45 a•45 b take up and crush flat the moving steelpipe 2 and feed the pipe 2 forward.

Ahead of the coupling part support 7 is provided the steel piperecovering part support 8.

As shown in FIGS. 18–20, the steel pipe recovering part support 8 has asecond roller conveyer 46 mounted at mid height, the steel piperecovering trolley 47 provided at a lower position under the secondroller conveyer 46, and the belt conveyer 48 provided at a higherposition above the second roller conveyer 46.

The steel pipe recovering trolley 47 is made to be freely movable in adirection perpendicular to the running direction of the crushed steelpipe 2′ from under the second roller conveyer 46 to a position clear ofthe second roller conveyer 46, (see FIG. 20).

At the fore end of the second roller conveyer 46 in the runningdirection of the crushed steel pipe 2′, a stopper 46 b of slender shapeto prevent further running of the crushed steel pipe 2′ is provided tobe perpendicular to the second roller conveyer 46 in such a manner asnot to interfere with the roller 46 a.

In combination with the slender stopper 46 b, at the rear end of thesteel pipe recovering part support 8, a pair of photoelectric tubes 8 a(emitter), 8 b (receiver) are provided to detect that the rear end ofthe crushed pipe 2′ has passed. Further, a push bar 8 c is provided topush the crushed, but still long, steel pipe 2′ in the directionperpendicular to the running direction thereof from back to fore and outof the second roller conveyer 46 in such a manner so as not to interferewith the rollers 46 a, the stopper 46 b, and the photoelectric tubes 8 a(emitter), 8 b (receiver). At the fore side in the directionperpendicular to the running direction of the crushed steel pipe 2′, aslide guide plate 8 d is provided rotatably on the frame of the steelpipe recovering part support 8 to properly guide the crushed steel pipe2′ to fall into the steel pipe recovering trolley 47.

When the separating and recovering apparatus is not being operated, theslide guide plate 8 d is turned upward, and in that condition, the steelpipe recovering trolley 47 is moved from outside the second rollerconveyer 46 to the position under the second roller conveyer 46 toeliminate dead space on the work floor.

The belt conveyer 48 is provided on the steel pipe recovering partsupport 8 at a position above the second roller conveyer 46 in such amanner that both ends thereof protrude from the steel pipe recoveringpart support 8, and is upwardly declined toward the smasher 49. Thus thebelt conveyer 48 can receive the crushed coating resin 3′ at the rearthereof and deliver the resin 3′ to the smasher 49 (see FIG. 1).

Ahead of the steel pipe recovering part support 8, the smasher support 9is provided

As shown in FIGS. 1,2,18 and 19, under the smasher support 9 the smasher49 is provided, which receives the crushed coating resin 3′ from thebelt conveyer 48 and smashes the resin 3′.

According to the composition of the recovering device 40 describedabove, the separated steel pipe and coating resin 3 can be recovered ina segregated condition in such a manner that each piece of the flatcrushed resin 3′ is smashed by the smasher 49 and the steel pipe 2 islead to the recovering trolley 47, with the steel pipe 2′ crushed flat,but unchanged in length, (according to the invention stated in Claims 2and 3).

As to the minimum suitable length of the resin-coated steel pipe 1 to beprocessed by the separating and recovering apparatus described above, itis preferable that the resin-coated steel pipe 1 is a little longer thanthe length with which, when the resin-coated steel pipe 1 is between thefeeding roll device 10 and the take-up roll device 30, which consist ofthree sets of feeding rolls and take-up rolls, respectively, the rearand the fore ends of the resin-coated steel pipe 1 can be locatedsimultaneously in the device 10 and the device 30, (the symbol S inFIGS. 1 and 3).

With the length described above, the resin-coated steel pipe 1 or thesteel pipe 2 can be stably supported and fed, and thereby makes itpossible to execute, also in a stable fashion, such operations as makingthe incision lines 18 in the resin-coated steel pipe 1, separating andsevering by the separating mechanism 25 and crushing the coating resin 3by the take-up roll device 30.

On the other hand as to the maximum suitable length, it is preferablethat the resin-coated steel pipe 1 is of such a length that when thefore end of the crushed steel pipe 3′ is at the stopper 8 b, the rearend thereof is a little ahead of the pair of photoelectric tubes 8 a(emitter) and 8 b (receiver), (the symbol L in FIGS. 1 and 8).

Smashed and recovered coating resin 3 can be recycled to be effectivelyused for new resin-coated steel pipe as inner coating resin on which newAAS resin or ABS resin is coated as the outer layer, withoutdeteriorating the quality of the finished resin-coated steel pipe.

FIGS. 21 and 22 are general front and plan views, respectively, of thesecond embodiment to practice the method to separate and recover steelpipe and coating resin from resin-coated steel pipe stated in Claim 1.

The resin-coated steel pipe 1 shown in FIG. 48 has as the inner resin oradhesion layer a on the surface of the steel pipe 2 a thin layer ofdenatured polyolefin having an adhesive character and a layer of uniformthickness of polyolefin (polyethylene or polypropylene) coated thereonas the outer resin, constituting a double-layer coating resin 3. On theinner surface of the steel pipe 2 is painted an antirust paint as a thinfilm to form an antirust layer b.

In FIGS. 21 and 22, from back to fore in the running direction of theresin-coated steel pipe 1 or the steel pipe 2, numeral 55 designates afeeder support, 56 designates a main part support, 57 coupling partsupport, and 58 steel pipe recovering part support.

On the main part support 56 are provided a feeding device 60, (having ameans to make incision lines), to feed the resin-coated steel pipe 1 ofarbitrary length in the running direction thereof, a high-frequencyinduction heating device that heats the resin-coated steel pipe 1 as thepipe passes inside or near a high-frequency induction coil 21, aseparating mechanism 75, (including a first run guide 27 as the rearpart of the run guide; see FIGS. 29–32), which, provided at anappropriate position reached immediately after passing thehigh-frequency induction coil 21, separate the coating resin 3 from thesteel pipe 2 and sever the coating resin 3, a take-up roll device 80,(including take-up rolls 81 that crush flat the coating resin 3; seeFIGS. 23,34–36), which takes up the steel pipe 2, and a second run guide82, (see FIGS. 23,24,29–32), which, as the fore part of the run guide,guides the crushed coating resin 3.

On the coupling part support 57 are provided a first roller conveyer 91,a crushing device 42 consisting of three sets of crushing rolls 43,44and 45, and a smasher 92. On the steel pipe recovering part support 58are provided a second roller conveyer 46 on the top surface thereof anda steel pipe recovering trolley 97 below the second roller conveyer 46.The recovering device 90 comprises the coupling part support 57, thesteel pipe recovering part support 58 and the devices and membersprovided on the coupling part support 57 and on the steel piperecovering part support 58, and recovers the separated steel pipe 2 andcoating resin 3 in segregated condition.

The FIGS. 23–29 show the second embodiment of the separating andrecovering apparatus.

For example, the resin-coated steel pipe 1 has an outer diameter of 27.7mm; the steel pipe 2 is of SPCC, (JIS G 3141 cold rolled steel plate &sheet; for general use); the steel pipe 2 is 25.5 mm in outer diameterand 0.7 mm in thickness; the thickness of the 2-layer coating resin is1.1 mm: the thickness of the inner resin or the adhesion layer a ofdenatured polyolefin (adhesive polyolefin) is 0.1 mm, and the meltingtemperature thereof is 140° C. while the softening temperature is 120°C.; the thickness of the outer resin of polyolefin (polyethylene orpolypropylene) is 1 mm, and the melting temperature thereof is about140° C. (in case of polyethylene) while the softening temperature is120° C. (in case of polyethylene).

With the conditions stated above, the running speed of the resin-coatedsteel pipe 1 moved by the feeding roll device 60 and the take-up rolldevice 80 is set to about 15 m/minite.

The running speed of 15 m/minite means that, using the separating andrecovering apparatus described in detail in the following, with thisspeed the resin-coated steel pipe 1 will be, arriving at the separatingmechanism 75, in such conditions that due to high-frequency inductionheating the adhesion layer is kept in a melted state while the outerlayer of the coating resin 3, separated from the steel pipe 2 andsevered, is not softened and has a surface temperature of 50° C.–60° C.,which is nearer to normal temperature than softening temperature,maintaining the rigidity sufficient for being solid.

In other words, with this running speed, the coating resin 3 attains thepreferred condition in which the layer of the coating resin 3 adjacentto the boundary of the steel pipe 2 has, at the separating mechanism 75,a temperature high enough to be separable from the steel pipe 2, whileat least the outer layer part of the coating resin 3 is kept at atemperature lower than necessary for softening, (according to theinvention stated in Claim 4).

With reference to FIGS. 26–28, the feeding device provided first in therunning course of the resin-coated steel pipe 1 on the main part support56 is described below.

The feeding device is shown as the feeding device 60 having two sets oftiming pulleys each consisting of two horizontally arranged pulleys61,62,63 and 64, two timing belts 65 and 66 and a set of feeding rolls13 arranged in series in the running course of the resin-coated steelpipe 1. Each of the two timing belts 65 and 66 is formed as usual on theinner side thereof with teeth, but on the outside also is formed withteeth and on the outside teeth is formed a peripheral groove 65 a or 66a having the curvature congruent to the outer surface of theresin-coated steel pipe 1.

Since the feeding device 60, the fixed and movable blocks, the forceadjusting mechanism, the set of feeding rolls provided on the side ofthe high-frequency induction coil, consisting of two division rollslocated at the upper and lower positions opposing each other to clampthe resin-coated steel pipe 1 and the incision blades provided on theset of feeding rolls are of the same composition, and have the samefunctions and effects as the fixed and movable blocks 14,15, the forceadjusting mechanism 16, the set of feeding rolls 13 and the incisionblades 17 described with the first embodiment of the separating andrecovering apparatus, they are given the same symbols as the devices andmembers having the functions, and a description is omitted.

The feeding device 60 is given force F on the division roll 13 a, thetiming belt 66 and the set of timing pulleys 63 and 64 incorporated inthe movable block 15 by the force adjusting mechanism 16 and throughengagement of the rotating peripheral grooves 65 a and 66 a of thetiming belts 65 and 66 and the peripheral grooves 13 c of the divisionrolls 13 a and 13 b with the outer surface of the resin-coated steelpipe 1, and feeds the resin-coated steel pipe 1 in the running directionthereof.

The high-frequency induction heating device 20 and the high-frequencyinduction coil 21 are almost the same as described in the explanation ofthe previous arts and the description thereof is omitted.

However, it should be noted that in the resin-coated steel pipe 1, thesteel pipe 2 is heated by means of high-frequency induction heating tosuch a condition that when the steel pipe 2 reaches the separatingmechanism 25 located at an appropriate position arrived at immediatelyafter heating process, the boundary layer of the coating resin 3 reachesa separable condition from the steel pipe 2 while the outer layer of thecoating resin 3, at least the surface layer of the outer resin thereofis kept under the softening temperature, (according to the invention ofClaim 4).

The embodiment of the separating mechanism 75 is described below withreference to FIGS. 29–33.

First, the resin-coated steel pipe 1 is given the incision lines 18•18at the upper and lower positions thereof. The separating mechanism 75 isprovided independently between the high-frequency induction coil 21 andthe take-up roll device 80. The separating mechanism 75 comprises a setof separating rolls 76 c consisting of two division rolls 76 d•76 dlocated at the upper and lower positions opposing the incision lines18•18 to clamp the resin-coated steel pipe 1 and the first run guide 27provided to enclose the resin-coated steel pipe 1 at a certain distance.

The set of separating rolls 76 c has a mechanism to give pressing forceto at least one of the division rolls 76 d•76 d against the outersurface of the steel pipe 2 toward the axis thereof, and the divisionrolls 76 d•76 d rotate with the peripheral surface thereof engaging theouter surface of the resin-coated steel pipe 1. The peripheral surfaceof each of the two division rolls 76 d•76 d can be formed into any shapeselected as preferable for the separating mechanism 75, for example, agable roof shape, (symbol 76 e in FIG. 32) or a shape having flat topwith a small semicircle, (symbol 77 a in the roll 77 shown in FIG. 33).

As the peripheral surface portions of the set of separating rolls 76 cfacing the high-frequency induction coil 21 come in contact with the twoincision lines 18•18 in the coating resin 3 of the resin-coated steelpipe 1 moving toward the peripheral surface portions, by exerting forceagainst the incision lines 18•18, the separating rolls 76 c separate thecoating resin 3, starting at the fore end thereof, from the steel pipe 2and sever the coating resin 3 along the incision lines 18•18 and awayfrom the steel pipe 2 into right and left pieces, which are guided bythe run guide 27 in the running direction of the coating resin 3.

It should be noted that there is no necessity to limit the arrangementof the incision lines 18•18 and the division rolls 76 d•76 d to theupper and lower positions, (according to the invention of Claim 10).

The embodiment of the separating mechanism 75 is described below indetail with reference to FIGS. 29–33.

The separating mechanism 75 described above comprises the division rolls76 d•76 d and the first run guide 27. In the event the two divisionrolls 76 d•76 d are provided, on the main body 76 fixed on the main partsupport 56 are mounted support frames 76 a•76 a and support axles 76b•76 b which support the two division rolls 76 d•76 d located at theupper and lower positions opposing each other to clamp the resin-coatedsteel pipe 1 in such a manner that the support axles 76 b•76 b arevertically adjustable with compression coil springs 76 f•76 f fitthereon.

The upper and lower support frames 76 a•76 a and support axles 76 b•76 bsupport at the fore ends thereof the division rolls 76 d•76 d and therear ends thereof protrude from the outside surface of the body 76. Onthe upper and lower end surfaces of the body 76 are provided stopwashers 76 g•76 g and through the stop washers 76 g•76 g extend the rearparts of the support axles 76 b•76 b respectively. Further, nuts 76 h•76h are provided on the back of the stop washers 76 g•76 g to clamp thestop washers 76 g•76 g.

In the clamped condition described above, if the compression coilsprings 76 f•76 f press the support axles 76 b•76 b and the stop washers76 g•76 g hit the body 76, this condition will define the forward limitposition of the division rolls 76 d•76 d.

At the forward limit position of the division rolls 76 d•76 d, thepositions of the central ridges of the peripheral surfaces 76 e•76 ehaving a gabled roof shape are set to protrude by a distance, 2 mm–3 mmfor example (symbol d in FIGS. 31,32), toward the axis of theresin-coated steel pipe 1 from the outer surface of the steel pipe 2 ofthe resin-coated steel pipe 1, which moves in the running directionthereof, and thereby desired forces f•f (see FIGS. 31,32) are givenagainst the outer surface of the passing resin-coated steel pipe 1 bythe compression coil springs 76 f•76 f through the division rolls 76d•76 d in the direction of the axis of the pipe 1.

Since the first run guide 27 is of the same composition and has the samefunction and effects as the first run guide 27 described in the firstembodiment of the separating and recovering apparatus, the devices andmembers having the same functions are given the same symbols and thedescription thereof is omitted.

According to the composition of the separating mechanism 75 describedabove, since the separating mechanism 75 never touches directly thesteel pipe 2 to scrape the coating resin 3 from the steel pipe 2, thereis no fear of cutting off dust of the steel pipe 2 and getting it intothe separated coating resin 3.

As the central ridges of the peripheral surfaces 76 e•76 e, which are ofa gabled roof shape and face the high-frequency induction coil 21, comein contact with the incision lines 18•18 made at the upper and lowerpositions of the coating resin 3 of the resin-coated steel pipe 1 movingin the running direction thereof, the forces f•f are exerted against theincision lines 18•18.

Therefore, the impacts that the resin-coated steel pipe 1 receives asthe forces f•f are exerted against the incision lines 18•18 of thecoating resin 3, generate repulsive forces (R in FIG. 32) toward rightand left acting on the fore ends of the coating resin 3 which is alreadycut into two, that is, right and left pieces by the incision lines 18•18on the periphery of the resin-coated steel pipe 1 and thereby thecoating resin 3 is separated from the steel pipe 2 and severed intoright and left pieces along the incision lines 18•18 and away from thesteel pipe 2 toward right and left, the only ways out for the respectivepieces.

The severed pieces of the coating resin 3 are guided by the run guide 27in the running direction thereof.

The separating mechanism 75 is provided between the high-frequencyinduction coil 21 and the take-up roll device 80 as taking up meansindependently and exclusively for separating operation, the performancethereof as separating means can be enhanced more.

The embodiment of the take-up device 80 as take-up means is describedbelow with reference to FIGS. 23,24 and 34–36.

As shown in FIGS. 23 and 24, the take-up roll device 80 comprises afixed block, a movable block and three sets of take-up rolls, and, sincethe composition that each of the three sets of the take-up rollsconsists of two division rolls located at the upper and lower positionsopposing each other, of which the lower one is incorporated in the fixedblock and the upper one is incorporated in the movable block, and that amechanism to give pressing force is incorporated in the combination ofthe fixed and the movable blocks are the same as the feeding roll device10 and the take-up device 30, having the same effects, the devices andmembers having the same functions are given the same symbols and thedescription thereof is omitted.

Of the three sets of the take-up rolls of the take-up roll device 80,the third set of the take-up rolls, that is, the two division rolls 81a•81 b in the take-up rolls 81 on the side of the recovering device 90,have greater width than the rolls in the sets 31 and 32 as shown in FIG.24, the flat portions 81 d•81 d of the periphery surface on the bothsides of the groove 81 c being accordingly wider. And, as shown in FIGS.14 and 15, the outer diameters of the division rolls 81 a•81 b locatedat the upper and lower positions are set to have such a clearancetherebetween as to be able to crush the right and left pieces of thecoating resin 3•3 into inwardly folded and flat condition.

On the flat portions 81 d of the upper division roll 81 b, two cuttingblades 81 e•81 e are attached at positions 180 degrees apart from eachother with a connecting bolt 81 g, for the purpose of not only crushing,but cutting the pieces of coating resin 3 into a determined length andthereby prevent the pieces of the coating resin 3 from being taken up bythe smasher 98, while the coating resin 3 is passing in the take-updevice 80 before being thrown in the smasher 98.

The second run guide 82 is provided in such a manner as to extend thelength, starting in the running direction of the coating resin 3 fromabout the middle point of the third set of the division rolls 81 a•81 b,to a point ahead of the take-up roll device 80, and so as not tointerfere with the take-up roll device 80 and the steel pipe 2, toconfine the crushed right and left pieces 3′•3′, (see FIGS. 23,24 and35), and to be bent downward at a point before the first roller conveyer91. By the second run guide 82, the pieces of the coating resin 3, whichare severed, crushed flat and cut into a determined length, are guidedto the smasher 98.

The number 82 a designates the mounting base provided in the secondguide 82.

Thus, the take-up roll device 80 feeds forward the steel pipe 2 byhaving the peripheral grooves of the division rolls take up the steelpipe 2 as the division rolls rotate. The flat portions 81 d•81 d of theperipheral surfaces on the both sides of the peripheral grooves 81 ctake up and crush the right and left coating resin pieces 3•3 moving inthe running direction into a folded and flat condition, andsimultaneously the cutting blades 81 e•81 e take up and cut the coatingresin pieces 3•3 into a determined length and send the cut pieces to thesecond run guide 82.

The second run guide 82 guides the coating resin pieces 3′•3′, crushedand cut into a determined length, to the smasher 99 described below.

According to the composition of the take-up roll device 80 describedabove, the take-up roll device 80 is able to crush flat the coatingresin pieces 33 separated from the steel pipe 2, and cut them intopieces of a determined length.

The embodiment of the recovering device is described below withreference to FIGS. 23,24 and 37–39.

Ahead of the main part support 56 is provided the coupling part support57 as the first support in the recovering device 90. As shown in FIGS.23,24, on the coupling part support 57, in the running direction of thesteel pipe 2, the first roller conveyer 91 is provided, which firstreceives the steel pipe 2 from the take-up roll device 30 and feedsforward the steel pipe 2, and, following the conveyer 91, the steel pipecrushing device 92, which crushes and feeds forward the steel pipe 2 isprovided.

Since the steel pipe crushing device is of the same composition and hasthe same function and effects as the steel pipe crushing device 42described in the first embodiment of the separating and recoveringapparatus as shown in FIGS. 23 and 24, the devices and members havingthe same functions are given the same symbols and the descriptionthereof is omitted.

Below the first roller conveyer 91 is mounted the smasher 98 having ahopper 98 a provided thereon, and the smasher 98 receives from thesecond run guide 82, which has the end thereof extending into the hopper98 a at the rear side thereof seen in the running direction of the steelpipe 2, the right and left coating resin pieces 3′•3, which are crushedand cut into a determined length, and smashes them.

Ahead of the coupling part support 57 is provided the steel piperecovering part support 58. As shown in FIGS. 37–39, the steel piperecovering part support 58 is provided with the second roller conveyer46 on the upper surface thereof and the steel pipe recovering trolley 97at the lower position. As shown in FIGS. 37–39, the second rollerconveyer 46 and the devices and members to push and guide the crushedsteel pipe 2′ from the second roller conveyer 46 into the steel piperecovering trolley 97, are the same as in the first embodiment of theseparating and recovering apparatus, are given the same symbols to thedevices and members having the same functions, and the descriptionthereof is omitted.

According to the composition of the recovering device 90 describedabove, the separated steel pipe 2 and coating resin 3 can be recoveredin segregated condition by smashing the pieces 3′ of the coating resin 3crushed flat and cut into a determined length, in the smasher 98 and byguiding the steel pipe 2′ crushed flat but having the original length,into the steel pipe recovering trolley 97 (according to the inventionstated in Claims 2 and 3).

The separating mechanism 105, which is the third embodiment as theseparating means, is described below with reference to FIGS. 40–42.

The separating mechanism 105 is provided independently between thehigh-frequency induction coil 21 and the take-up device. The separatingmechanism 105 comprises the sucking device 106 that has a plurality ofsucking surfaces 106 b, which surround the resin-coated steel pipe 1 andattract the outer surface of the coating resin 3, and a run guide 107provided at a distance from the steel pipe 2 enclosing the pipe 2.

The sucking device 106 has the sucking surfaces 106 b in such a manneras to diverge in distance from each other in the direction from thehigh-frequency induction coil 21 to the take-up device to pull away thecoating resin 3 from the steel pipe 2. Passing the resin-coated steelpipe 1, which has the coating resin 3 divided into at least two partsalong the sucking surfaces 106 b of the sucking device 106 in action,the sucking device 106 attracts the pieces of the coating resin 3 andseparates the coating resin 3, starting at the fore end thereof, fromthe steel pipe 2, and severs the coating resin 3 along the incisionlines 18 and away from the steel pipe 2 into two pieces which are guidedby the run guide 107 in the running direction thereof, (according to theinvention stated in Claim 11).

In greater detail, the sucking device 106 has a pair of sucking surfaces106 b arranged inside a sucking cylinder 106 a on the left and rightsides to enclose the resin-coated steel pipe 1 corresponding to theupper and lower positions of the incision lines 18•18, and the twosucking surfaces 106 b have numerous sucking holes 106 c of a smalldiameter, (0.5 mm–1.0 mm, for example). The symbol 106 d designates asucking pipe.

The run guide 107, enclosing the steel pipe 2, extends the lengthbetween the position a little before the sucking pipe 106 a and theposition ahead of the take-up roll device 30, or 80, arranged in such amanner as not to interfere with the take-up roll device 30 or 80, andconstitutes the rear part of the run guide having the right and leftpieces 107 a•107 a and the lower piece 107 at a distance from the steelpipe 2.

According to the composition of the separating mechanism 105 describedabove, since the separating mechanism 105 never contacts with the steelpipe 2 to scrape the coating resin 3 from the steel pipe 2, there is nofear of cutting dust of the steel pipe 2 getting into the separatedcoating resin 3. By the sucking action of the sucking device 106 on theresin-coated steel pipe 1, which has the coating resin 3 divided into atleast two parts and passes between the sucking surfaces 106 b of thesucking device 106 in action, the pieces of the coating resin 3 aresucked to the right and left, (symbol V in FIG. 42) while running, andare thereby separated, starting at the fore end thereof, from the steelpipe 2 and severed along the incision lines 18 and away from the steelpipe 2 into two pieces. The severed pieces of the coating resin 3 arethen guided by the run guide 107 in the running direction of the pipe.

The separating mechanism 105 is provided between the high-frequencyinduction coil 21 and the take-up roll device independently andexclusively for separating operation, which means that the performancethereof as separating means can further enhanced.

The separating mechanism 115 is described below as the fourth embodimentof the separating mechanism with reference mainly to FIGS. 43–46.

The separating mechanism 115 is different from the separating mechanism25, the separating mechanism 75 and the separating mechanism 105, andcan be, for example, incorporated in the set of the take-up rolls 31 ofthe take-up device 30 provided on the side of the high-frequencyinduction coil 21. First, the resin-coated steel pipe 1 is provided atthe upper and lower positions with the incision lines 18•18. With theseparating mechanism 115, the take-up device is constructed as thetake-up roll device 30′ consisting of at least two sets of take-up rollsof which one has two division rolls as the take-up rolls.

In the take-up roll device, the prescribed division rolls are givenpressing force against the outer surface of the steel pipe 2 toward theaxis thereof and take up the steel pipe 2 through rotation andengagement of the peripheral surfaces of the division rolls with theouter surface of the steel pipe 2. The separating mechanism 115 has inthe take-up device 30′ a set of take-up rolls 116 which are eitherformed or not on the periphery with a groove 116 c of depth about ⅓ to ¼of the radius of the steel pipe 2 or less and positioned on the side ofthe high-frequency induction coil 21, and has the run guide 117enclosing the steel pipe 2 at a distance from it.

In the take-up roll device 30′, as the peripheral portions of thegrooves 116 c, 116 c a set of division rolls 116 a•116 b facing thehigh-frequency induction coil 21 come in contact with the two incisionlines 1818 in the coating resin 3 of the resin-coated steel pipe 1moving toward the peripheral surface portions, by exerting force againstthe incision lines 18•18, the division rolls 116 a•116 b separate thecoating resin 3, starting at the fore end thereof, from the steel pipe 2and sever the coating resin 3 along the incision lines 18•18 and awayfrom the steel pipe 2 into right and left pieces, which are guided bythe run guide 117 in the running direction of the pieces of the coatingresin 3.

The arrangements of the incision lines 18•18 and the division rolls 116a•116 b are not limited to the upper and lower positions, (according tothe invention of Claim 8).

The embodiment of the separating mechanism 115 is described below indetail with reference to FIGS. 43–46.

The take-up device 30′ consists of the three sets of take-up rolls116,32 and 33, of which one set has as take-up rolls upper and lowerdivision rolls. The take-up device 30′, in a similar manner as thetake-up device 30, by means of the force adjusting mechanism 16, givesthe pressing force F to the division roll 116 b incorporated in theupper movable block 15 toward the axis of the steel pipe 2. The divisionroll 116 a incorporated in the upper movable block 14 also exerts as thereaction the force F′ having the same magnitude as F against the steelpipe 2 toward the axis thereof.

The separating mechanism 115 comprises the set of take-up rolls 116which, positioned on the side of the high-frequency induction coil 21,has the division rolls 116 a•116 b that are given a pressing forcetoward the axis of the steel pipe 2, the division rolls 116 a•116 bbeing either formed or not on the periphery with a groove 116 c of depthabout ⅓ to ¼ of the radius of the steel pipe 2 or less and the guide117, which, opposing each other and enclosing the steel pipe 2, extendsthe length starting from a point a little before the two division rolls116 a•116 b to a point ahead of the take-up roll device 30′ in such amanner as not to interfere with the take-up roll device 30′ andconstitutes the rear part of the run guide which consists of the rightand left pieces 117 a•117 a provided on the sides of the steel pipe 2 ata distance and the lower piece 117 b.

The condition in which the lower surface of the movable block 15contacts the upper surface of the bases 16 a′•16 a′ of the standingaxles 16 a•16 a defines the limit advanced position (the lowestposition) of the division roll 116 b incorporated in the movable block15, (see FIG. 44).

In this limit advanced position of the division roll 116 b, the positionof the peripheral groove 116 c or the peripheral surface of the divisionroll 116 b in the direction toward the axis of the steel pipe 2 is setin such a manner that the peripheral groove 116 c or the peripheralsurface protrudes from the outer surface of the steel pipe 2, whichcomes forward by a quantity of 1 mm–2 mm, for example (symbol D in FIG.44).

In this condition, when the portions of the peripheral groove 116 c•116c or the peripheral surfaces facing the high-frequency induction coil 21come in touch with the incision lines 18•18 (symbol P in FIG. 44) madeat the upper and lower positions in the coating resin 3 of theresin-coated steel pipe 1 that comes toward the rolls 116 a•116 b, firstthe division roll 116 b exerts force F against one of the incision line18•18 and a little after that the division roll 116 a exerts force F′against the other incision line 18.

According to the separating mechanism 115 described above, since theseparating mechanism 115 never touches directly the steel pipe 2 toscrape the coating resin 3 from the steel pipe 2, there is no fear ofcut off dust of the steel pipe 2 getting into the separated coatingresin 3. And, when the portions of the peripheral groove 116 c•116 c orthe peripheral surfaces facing the high-frequency induction coil 21 comein touch with the incision lines 18•18 made at the upper and lowerpositions in the coating resin 3 of the resin-coated steel pipe 1 thatcanes toward the rolls 116 a•116 b, forces F and F′ are exerted againstthe incision line 18.

Therefore, the impacts that the resin-coated steel pipe 1 receives asthe forces F•F′ are exerted against the incision lines 18•18 of thecoating resin 3, generate repulsive forces (R in FIG. 46) toward theright and left, acting on the fore ends of the coating resin 3, which isalready divided into two, that is, right and left pieces by the incisionlines 18•18 on the periphery of the resin-coated steel pipe 1 and as thefore ends of the coating resin 3 runs beyond the peripheral grooves 116c or the peripheral surfaces the coating resin 3 is not only separatedfrom the steel pipe 2 but beyond the peripheral grooves 116 c or theperipheral surfaces completely severed into right and left pieces alongthe incision lines 18•18, and away from the steel pipe 2 toward rightand left, the only escape ways out for the respective pieces. Thesevered pieces of the coating resin 3 are guided by the run guide 117 inthe running direction of the pipe.

Further, the separating mechanism 115 has the division rolls 116 a•116 bthat exert forces against the incision lines 18•18 at the upper andlower positions of the coating resin 3, and since the set of take-uprolls 116 is incorporated in the take-up roll device 30′, the minimumsuitable length of the resin-coated steel pipe 1 processed by theseparating and recovering apparatus determined by the distance betweenthe feeding device 10 and the take-up device 30′ can be reduced, (seesymbol S′ in FIG. 43).

The separating mechanism 125 is described below as the fifth embodimentof the separating mechanism based on FIG. 47.

The resin-coated steel pipe 51 has a square section and is made byadhering coating resin 53 on steel pipe 52. The coating resin 53 has athick side 53 a on which an L shaped rib 53 b is provided to form agroove 53 c. In the groove 53 c is to be fit in a suitable panel member55.

The dimensions of section of the resin-coated steel pipe 51 are about27.7 mm×27.7 mm.

Symbol 54 designates a socket part of a suitable joint to connect theresin-coated steel pipe 51 and in the socket 54 the outer surfacethereof is flush with the outer surface of the thick side 53 a.

The incision lines 18 are provided at three positions of the coatingresin 53, that is, when the section is seen with the thick side 53 a asthe upper side, two in the right and left sides at points near the thickside 53 a and one at the center of the lower side.

The separating mechanism 125 is provided independently between thehigh-frequency induction coil and the take-up roll device as theseparating mechanism 25, the separating mechanism 75 and the separatingmechanism 105, (not shown in the drawings).

In the separating mechanism 125, three dividing blades 127,127,127 arefixed, with the same considerations as with respect to the separatingmechanism 25, on the body 126 at positions corresponding to the threeincision lines 18•18•18 in such a manner that the pointed ends thereofrespectively oppose the incision lines in the coating resin 53 of theresin-coated steel pipe 51 moving in the running direction. Adjacent tothe thick side 53 a is provided a sucking cylinder 128.

A run guide 129 having right and left pieces 129 a and 129 b and a lowerpiece 129 c is provided at a distance from the resin-coated steel pipe51 and at a little lowered position in such a manner so as not tointerfere with the resin-coated steel pipe 51 and the separatingmechanism 125.

By the splitting and spreading action of the three dividing blades127,127,127 (symbol B in FIG. 47) and by the sucking action of thesucking cylinder 128 (symbol V in FIG. 47), the coating resin 53 is,starting at the fore end thereof, separated from the steel pipe 52 andsevered along the incision lines and away from the steel pipe 52 intotwo pieces which are guided by the run guide 129 in the runningdirection of the pipe.

According to the composition of the method and the apparatus to separateand recover steel pipe and coating resin from resin-coated steel pipedescribed above, the resin-coated steel pipe 1,51 made by adheringthermo-plastic resin 3,53 on steel pipe 2,52 is, at the position alittle before passing the high-frequency induction coil 21, alreadygiven the incision lines 18, which reach in depth from the surface ofthe coating resin 3,53 to the surface of the steel pipe 2,52, by anincision means throughout the length of the resin-coated steel pipe 1,51and has the coating resin 3,53 circumferentially divided precisely intoat least two parts.

By high-frequency induction heating, the steel pipe 2,52 is heated, bythe time it reaches the separating mechanism 25,75,105,115,125 locatedat an appropriate position arrived at immediately after heating process,to a temperature at which the bottom layer of the coating resin 3,53adjacent to the boundary of the steel pipe 2,52 reaches a conditionseparable from the steel pipe 2,52, while the outer layer of the coatingresin 3,53, at least the outer half thereof is kept under the softeningtemperature.

The separating mechanism 25,75,105,115 or 125 separates the coatingresin 3,53 from the steel pipe 2,52 through separation and does notscrape off the coating resin 3,53 from the steel pipe 2,52 by theincision blades or other tools that are tightly fit to the sectioncontour of the moving steel pipe 2,52, thereby generating friction.

Further, by the separating mechanism 25,75,105,115 or 125, the coatingresin 3,53 is separated from the steel pipe 2,52 and severed along theincision lines 18 and away from the steel pipe 2,52 into at least twopieces, which are guided by the run guide in the running directionthereof.

After that, the steel pipe 2′ and the coating resin 3′, separated andcrushed flat, are recovered by the recovering device 40,90 in segregatedcondition.

This invention is not construed as limited to the particular formsdisclosed herein.

As a means to make incision lines, for example, in addition to incisionblades, laser beam, supersonic waves, etc., can be utilized. Or themeans to make incision lines may be installed separately from thefeeding device.

INDUSTRIAL UTILIZATION

According to the method and apparatus to separate steel pipe and coatingresin from resin-coated steel pipe stated in Claim 1 and 13, thefollowing effects can be expected:

-   1) At the position before passing the high-frequency induction coil,    the incising means are capable of making the incision lines that    reach in depth from the surface of the coating resin to the surface    of the steel pipe, and can thereby divide the steel pipe 2,52    circumferentially precisely into at least two parts.

Thus, since the coating resin will certainly maintain this dividedcondition after passing the high-frequency induction coil, in theprocess executed by the separating mechanism provided at a positionarrived at immediately after passing the high-frequency induction coil,the coating resin will certainly be, starting at the fore end thereof,separated from the steel pipe and severed along the incision lines andaway from the steel pipe into at least two pieces, which pieces areguided by the run guide in the running direction of the pipe, and thesevering and guiding process being continued, the coating resin issevered throughout the length of the pipe along the incision lines intoat least two pieces.

-   2) Since the steel pipe is heated by the high-frequency induction    heating to a condition such that the layer of the coating resin    adjacent to the boundary of the steel pipe is separable at the    separating mechanism, the separating mechanism is able to separate    the coating resin which is circumferentially divided into two parts    from the steel pipe, by peeling, without scraping the coating resin    off the steel pipe which produces pieces or dust of the steel pipe,    eliminating the fear that the cut off pieces or dust of the steel    pipe will get into the recovered coating resin.

The recovered coating resin can, therefore, be easily recycled for use.

-   3) The separating mechanism does not scrape the coating resin from    the steel pipe by blades or other tools that are tightly fit to the    section contour of the moving steel pipe, thereby also generating    friction, and there is no fear that the separated coating resin will    stick or accumulate.

Therefore, the apparatus can be operated continuously.

According to the method and apparatus to separate steel pipe and coatingresin from resin-coated steel pipe stated in Claims 2–12, in addition tothe effects of Claims 1 and 13, the following effects can be expected:

According to the invention stated in Claim 2, the coating resin severedalong the incision lines and away from the steel pipe into at least twopieces is recovered by the recovering device in flat-crushed andappropriately smashed condition. Each piece of severed coating resinwhich is crushed into flat condition before smashing process turns moreeasily to the crushed side, which means that the part of the apparatusfrom the take-up device to the recovering device can be selectivelydesigned and practiced preferably to locate the smasher, etc., atsuitable positions to utilize the fact that the crushed resin pieces canbe made to change direction more easily to the crushed side.

Therefore, in one apparatus for separating and recovering, the wholeoperation, from supplying resin-coated steel pipes to recoveringseparated coating resin, can be executed in a consistent preferredmanner.

According to the invention stated in Claim 3, the steel pipe isrecovered after being crushed into flat and reduced in volume, with thelength remaining the same.

Therefore, in one apparatus for separating and recovering, the wholeoperation, from supplying resin-coated steel pipes to recoveringseparated coating resin, can be executed in a consistent preferredmanner.

According to the invention stated in Claim 4, since the separatingmechanism separates the coating resin circumferentially cut into twoparts from the steel pipe when the steel pipe is heated by means ofhigh-frequency induction heating to a temperature at which the layer ofthe coating resin adjacent to the boundary of the steel pipe reaches acondition separable from the steel pipe, while at least the exteriorside of the outer layer of the coating resin is kept under thetemperature at which softening occurs, the pieces of the separatedcoating resin maintain adequate rigidity.

The pieces of the separated coating resin are, therefore, easily guidedin a determined course by the run guide and can easily be recovered.

According to the stated in Claim 5, the feeding roll device consists oftwo or two or more sets of feeding rolls and the incision blades asmeans to make incision lines are provided in one set of feeding rolls.

Therefore, to provide the means to make incision blades does not resultin an increase in size of the apparatus, which means that savings on themanufacturing cost of the apparatus are possible.

According to the invention stated in Claim 6, in addition to the effectsof Claim 5, the following effects can be expected:

In the feeding roll device, the incision blades are provided in the setof feeding rolls, which, located on the side of the high-frequencyinduction coil, consists of rolls given pressing force toward the axisof the resin-coated steel pipe.

Therefore, the resin-coated steel pipe is stably supported at theportion behind the set of the feeding rolls on the side of thehigh-frequency induction coil by the remaining sets of the feedingrolls, which enables the stable making of incision lines throughout thelength of the resin-coated steel pipe.

According to the invention stated in Claim 7, in addition to the effectsof Claim 5 and 6, the following effects can be expected:

The incision blades have the edge angle not greater than about 30degrees and can cut the coating resin neatly without squashing theresin.

Therefore, the cut condition of the coating resin is maintainednaturally not only before but also after the coating resin passes thehigh-frequency induction coil.

According to the invention stated in Claim 8, the separating mechanismhas the take-up roll device consisting of two or more sets of take-uprolls, each having two division rolls, one set of take-up rolls which,located on the side of the high-frequency induction coil, includes theroll given pressing force toward the axis of the rein-coated steel pipeand have the peripheral surfaces either formed with peripheral groovesor not, and the run guide provided at a distance from the steel pipe toenclose it, and the portions of the peripheral grooves or surfaces ofthe set of take-up rolls facing the high-frequency induction coil exertforce against the two incision lines in the coating resin of theresin-coated steel pipe, which runs toward the grooves or surfaces.

Therefore, the impact that the resin-coated steel pipe receives asforces are exerted against the incision lines of the coating resin,generate repulsive forces toward the right and left acting on the foreends of the coating resin which is already divided into two, that is,right and left pieces by the incision lines on the periphery of theresin-coated steel pipe, and thus, the coating resin is separated andpeeled from the steel pipe and run beyond the grooves or the surfaces,severed into right and left pieces along the incision lines, and awayfrom the steel pipe toward right and left, the only ways out for therespective pieces. As the severing and guiding process is continued, thecoating resin is severed throughout the length of the pipe along theincision lines into two right and left pieces.

Further, the separating mechanism has in the take-up roll device one setof take-up rolls incorporated therein which, located on the side of thehigh-frequency induction coil, exert force against the two incisionlines in the coating resin. This means the minimum suitable length ofthe resin-coated steel pipe determined by the distance between thefeeding device and the take-up device can be reduced, making it possibleto process shorter resin-coated steel pipes for separating andrecovering steel pipe and the coating resin.

Furthermore, the separating mechanism, if provided, can be incorporatedin the take-up roll device, without an increase in size of theapparatus, which means that savings on the manufacturing cost of theapparatus are possible.

According to the invention stated in Claim 9, the separating mechanismis provided independently between the high-frequency induction coil andthe take-up device and comprises the dividing blades constructed in theprescribed manner and the run guide arranged at a distance to enclosethe steel pipe, the pointed tips of the blades being made to hit theincision lines in the coating resin of the resin-coated steel pipe.

Therefore, by the dividing and spreading action of the pointed tips ofthe dividing blades against the coating resin, divided into parts by theincision lines provided therein, the coating resin is, starting at thefore end thereof, as the parts run in diverging directions, separatedfrom the steel pipe and severed along the incision lines and away fromthe steel pipe into at least two pieces. The severed pieces of thecoating resin are then guided in the running directions of the pipe bythe run guide. As the severing and guiding process is continued, thecoating resin is severed throughout the length of the pipe along theincision lines into at least two pieces. Thus, the operations describedabove are executed more securely.

According to the invention stated in Claim 10, the separating mechanismis provided independently between the high-frequency induction coil andthe take-up device and comprises the set of division rolls consisting oftwo rolls of which one roll is given force against the surface of thesteel pipe toward the axis thereof and the run guide provided at adistance from the steel pipe to enclose it, the two division rolls beingof such construction that the portions of the surfaces of the twodivision rolls facing the high-frequency induction coil exert forceagainst the two incision lines in the coating resin of the resin-coatedsteel pipe which comes running toward the surfaces and the two divisionrolls have the peripheral surfaces formed with the selected prescribedshape.

Therefore, the impact that the resin-coated steel pipe receives asforces is exerted against the incision lines of the coating resin,generate repulsive forces toward right and left acting on the fore endsof the coating resin, which is already cut into two, that is, right andleft pieces by the incision lines on the periphery of the resin-coatedsteel pipe, and thus the coating resin is separated and peeled from thesteel pipe and severed into right and left pieces along the incisionlines and away from the steel pipe toward right and left, the only waysout for the respective pieces. The severed pieces are then guided in therunning direction of the pipe by the run guide. As the severing andguiding process is continued, the coating resin is severed throughoutthe length of the pipe along the incision lines into two right and leftpieces. The operations described above are executed more securely.

According to the invention stated in Claim 11, the separating mechanismis provided independently between the high-frequency induction coil andthe take-up device and comprises a sucking device having suckingsurfaces of prescribed construction and the run guide provided at adistance from the steel pipe to enclose it, and the resin-coated steelpipe having the coating resin divided into at least two parts and movingin the running direction of the pipe passes through the sucking devicein sucking action.

Therefore, by the sucking action of the sucking device on the coatingresin of the passing resin-coated steel pipe, the parts of the coatingresin are sucked to individual directions while running and the coatingresin is, starting at the fore end thereof, thereby separated and peeledfrom the steel pipe and severed along the incision lines and away fromthe steel pipe into at least two pieces. The severed pieces are thenguided in the running direction thereof by the run guide. As thedividing and guiding process is continued, the coating resin is severedthroughout the length thereof along the incision lines into two rightand left pieces. The operations described above are executed moresecurely.

According to the invention stated in Claim 12, the incision lines aremade at the upper and lower positions and the separating mechanism hasthe run guide constituting of the right and left pieces and the lowerpiece located at a distance from the steel pipe to enclose it.

Therefore, the means to make incision lines and the separating mechanismcan be both constructed simply by giving them a consistent, mutualrelation.

Further, the whole construction from the means to make incision linesand to the take-up device can also be made rational and simple.

1. A method to separate and recover steel pipe and coating resin fromresin-coated steel pipe, intended to process a resin-coated steel pipewhich consists of steel pipe and coating resin adhered to an outersurface of said pipe, employing a separating and recovering apparatushaving a feeding device, a high-frequency induction heating device, aseparating mechanism, a take-up device and a recovering device, saidfeeding device feeding said resin-coated steel pipe of certain length ina running direction thereof thereby passing and heating saidresin-coated steel pipe inside or near a high-frequency induction coilof said high-frequency induction heating device, said separatingmechanism, which is located at a certain position reached immediatelyafter a heating process separating said coating resin from said steelpipe, said take-up device taking up said steel pipe in said runningdirection thereof and said recovering device recovering said separatedsteel pipe and coating resin, characterized in that a cutting meanslocated at a position before said high-frequency induction coil makesincision lines in said coating resin that reach in depth from a surfaceof said coating resin to said surface of said steel pipe and extendthroughout a length of said resin-coated pipe at positions that divide aperiphery of said coating resin into at least two parts, that by meansof high-frequency induction heating, said steel pipe is heated in such amanner that, when it reaches said separating mechanism located at anappropriate position arrived at immediately after a heating process, abottom layer of said coating resin adjacent to a boundary of said steelpipe reaches a condition separable from said steel pipe, that saidseparating mechanism separates said coating resin from said steel pipeand severs said coating resin along said incision lines and away fromsaid steel pipe into at least two pieces and then guides severed piecesof said coating resin in said running direction thereof, and that saidrecovering device recovers said resin pieces by smashing said resinpieces that are crushed flat in prescribed processes, including ataking-up process by said take-up device.
 2. A method to separate andrecover steel pipe and coating resin from resin-coated steel pipe,intended to process a resin-coated steel pipe which consists of steelpipe and coating resin adhered to an outer surface of said pipe,employing a separating and recovering apparatus having a feeding device,a high-frequency induction heating device, a separating mechanism, atake-up device and a recovering device, said feeding device feeding saidresin-coated steel pipe of certain length in a running direction thereofthereby passing and heating said resin-coated steel pipe inside or neara high-frequency induction coil of said high-frequency induction heatingdevice, said separating mechanism, which is located at a certainposition reached immediately after a heating process, separating saidcoating resin from said steel pipe, said take-up device taking up saidsteel pipe in said running direction thereof and said recovering devicerecovering separated steel pipe and coating resin, characterized in thata cutting means located at a position before said high-frequencyinduction coil makes incision lines in said coating resin that reach indepth from a surface of said coating resin to said surface of said steelpipe and extend throughout a length of said resin-coated pipe atpositions that divide a periphery of said coating resin into at leasttwo parts, that by means of high-frequency induction heating, said steelpipe is heated in such a manner that, when it reaches said separatingmechanism located at an appropriate position arrived at immediatelyafter a heating process, a bottom layer of said coating resin adjacentto a boundary of said steel pipe reaches a condition separable from saidsteel pipe, that said separating mechanism separates said coating resinfrom said steel pipe and severs said coating resin along said incisionlines and away from said steel pipe into at least two pieces and thenguides severed pieces of said coating resin in said running directionthereof, and that said recovering device recovers said steel pipe aftercrushing it into a flat condition but maintaining an original lengththereof.
 3. A method to separate and recover steel pipe and coatingresin from resin-coated steel pipe according to claim 2 or characterizedin that by means of high-frequency induction heating, said steel pipe isheated in such a manner that, when it reaches said separating mechanismlocated at an appropriate position arrived at immediately after aheating process, said layer of said coating resin adjacent to saidboundary of said steel pipe reaches a condition separable from saidsteel pipe, but at least said exterior side of said outer layer of saidcoating resin is kept under a temperature at which softening occurs. 4.A method to separate and recover steel pipe and coating resin fromresin-coated steel pipe according to any of claim 1–3 characterized inthat said feeding device is constructed as a feeding roll deviceconsisting of two or more sets of feeding rolls, each of said sets offeeding rolls having a plurality of division rolls, that said feedingroll device has a construction such that a prescribed division roll isgiven pressing force against said outer periphery of said resin-coatedsteel pipe toward an axis of said resin-coated steel pipe, and a grooveformed on a periphery of each of said division rolls engages with saidouter periphery of said resin-coated steel pipe and rotates to therebyfeed said resin-coated steel pipe in said running direction thereof,that in said set of feeding rolls of said feeding device, which havesaid division roll that is given pressing force against said outerperiphery of said resin-coated steel pipe toward said axis thereof andwhich are arranged to clamp said resin-coated steel pipe, at a bottom ofgrooves of at least two of said division rolls, are provided throughoutperiphery incision blades of which tips are protruding, that said tip ofsaid incision blade protrudes from said bottom of said groove by aheight no less than a thickness of said coating resin, and that as saidfeeding device feeds said resin-coated steel pipe in said runningdirection thereof, said incision blades that are forced against saidresin-coated steel pipe make incision lines.
 5. A method to separate andrecover steel pipe and coating resin from resin-coated steel pipeaccording to any of claim 4 characterized in that said incision bladesare provided in said set of feeding rolls, which includes said divisionroll that is given a force toward said axis of said resin-coated steelpipe and is located on a side of said high-frequency induction coil. 6.A method to separate and recover steel pipe and coating resin fromresin-coated steel pipe according to claim 4 or characterized in that anedge angle of said incision blades is about 30 degrees or less.
 7. Amethod to separate and recover steel pipe and coating resin fromresin-coated steel pipe according to any of claim 1–3 characterized inthat said resin-coated steel pipe is given two incision lines, that saidtake-up device is constructed as a take-up roll device that consists oftwo or more sets of take-up rolls of which one has as take-up rolls twodivision rolls which are arranged opposing each other precisely on saidincision lines to clamp said steel pipe, that said take-up roll devicehas a construction such that said prescribed division roll is givenpressing force against said outer periphery of said steel pipe towardsaid axis of said resin-coated steel pipe, and said periphery of each ofsaid division rolls thereby engages with said outer periphery of saidsteel pipe and rotates to take up said steel pipe in said runningdirection thereof, that a separating mechanism comprises, in saidtake-up roll device, a set of take-up rolls which, including a divisionroll given pressing force toward said axis of said steel pipe, arepositioned on a side of said high-frequency induction coil and which areeither formed or not on a periphery with grooves of depth about ⅓ to ¼of a radius of said steel pipe or less, and a run guide provided at adistance from said steel pipe to enclose said steel pipe and that insaid take-up roll device, when, on two division rolls in said set oftake-up rolls that is positioned on said side of said high-frequencyinduction coil, portions of said periphery grooves or said peripherysurfaces facing said high-frequency induction coil come in touch withsaid incision lines in said coating resin of said moving resin-coatedsteel pipe, through forces given to said two incision lines, saidcoating resin is, starting at a fore end thereof, separated from saidsteel pipe and severed along said incision lines and away from saidsteel pipe into two pieces and then guided by said run guide in saidrunning direction thereof.
 8. A method to separate and recover steelpipe and coating resin from resin-coated steel pipe according to any ofclaim 1–3 characterized in that said separating mechanism is providedbetween said high-frequency induction coil and said take-up device, thatsaid separating mechanism comprises said dividing blades fixed atpositions corresponding to said incision lines which divide said coatingresin circumferentially into at least two parts in such a manner thatpointed tips of said dividing blades oppose said incision lines in saidcoating resin of said resin-coated steel pipe, which comes moving in arunning direction thereof and said run guide located at a distance fromsaid steel pipe to enclose said steel pipe, that as said pointed ends ofsaid dividing blades strike against said incision lines made in saidcoating resin of said resin-coated steel pipe moving in said runningdirection, said coating resin is, from said fore end thereof, separatedfrom said steel pipe along said incision lines and away from said steelpipe, and severed into at least two pieces which are guided by said runguide in said running direction thereof.
 9. A method to separate andrecover steel pipe and coating resin from resin-coated steel pipeaccording to any of claim 1–3 characterized in that said separatingmechanism is provided between said high-frequency induction coil andsaid take-up device, that said separating mechanism comprises a set ofsevering rolls consisting of two division rolls that are arranged tooppose each other at positions corresponding to said incision lines toclamp said resin-coated steel pipe and a run guide that is provided at adistance from said steel pipe to enclose said steel pipe, and that insaid set of severing rolls, at least one division roll is given a forceagainst said outer surface of said steel pipe toward said axis thereofand said two division rolls rotate with a periphery thereof engagingwith said outer surface of said steel pipe, that said periphery of eachof said two division rolls is formed into a shape selected as apreferred one for said separating mechanism, and that in said set ofsevering rolls, when portions of said periphery surfaces facing saidhigh-frequency induction coil come in touch with said incision lines insaid coating resin of said moving resin-coated steel pipe, through forcegiven to said two incision lines, said coating resin is, starting atsaid fore end thereof, separated from said steel pipe and severed alongsaid incision lines and away from said steel pipe into two pieces, whichare then guided by said run guide in said running direction thereof. 10.A method to separate and recover steel pipe and coating resin fromresin-coated steel pipe according to any of claim 1–3 characterized inthat said separating mechanism is provided between said high-frequencyinduction coil and said take-up device, that said separating mechanismcomprises a sucking device that has a plurality of sucking surfaceswhich, surrounding said resin-coated steel pipe, attract an outersurface of said coating resin and a run guide provided at a distancefrom said steel pipe enclosing said pipe, that said plurality of suckingsurfaces diverge in distance therebetween in a direction from saidhigh-frequency induction coil to said take-up device to pull away saidcoating resin from said steel pipe, that as said resin-coated steel pipewhich has said coating resin divided into at least two parts movesthrough said plurality of sucking surfaces of said sucking device, saidsucking device attracts each piece of said coating resin and, therebyseparating said coating resin, starting at said fore end thereof, fromsaid steel pipe, sever said coating resin along said incision lines andaway from said steel pipe into at least two pieces, which are guided insaid running direction thereof by said run guide.
 11. A method toseparate and recover steel pipe and coating resin from resin-coatedsteel pipe according to any of claim 1–3 characterized in that saidresin-coated steel pipe is given two incision lines at an upper andlower positions, that said separating mechanism is provided with a runguide consisting of right and left guide pieces located on either sideof said steel pipe and a lower piece located below said pipe at adistance from said pipe to avoid interference with said separatingmechanism, and that said separating mechanism separates said coatingresin, starting at said fore end thereof, from said steel pipe and seversaid coating resin along said incision lines and away from said pipeinto left and right pieces which are guided by said run guide in saidrunning direction thereof.
 12. An apparatus to separate and recoversteel pipe and coating resin from resin-coated steel pipe, intended toprocess a resin-coated steel pipe which consists of steel pipe andcoating resin adhered to an outer surface of said pipe, comprising afeeding device which feeds said resin-coated steel pipe of any length ina running direction thereof, a high-frequency induction heating devicewhich heats said resin-coated steel pipe passing inside or near ahigh-frequency induction coil, a separating mechanism which, provided atan appropriate position reached by said moving resin-coated steel pipeimmediately after passing an induction coil, separates said coatingresin from said steel pipe, a take-up device and a recovering devicewhich recovers steel pipe and coating resin in segregated condition,characterized in that a means is provided at a position before saidhigh-frequency induction coil to make incision lines in a surface ofsaid resin-coated steel pipe at locations for division into at least twopieces in such a manner that said incision lines reach in depth fromsaid surface of said coating resin to said surface of said steel pipe,that said high-frequency induction heating device is capable of heatingsaid steel pipe by means of high-frequency induction into a conditionsuch that, at a position of said separating mechanism, a bottom layer ofsaid coating resin adjacent to a boundary of said steel pipe isseparable from said steel pipe, and that said separating mechanism isconstructed in such a manner as to be able to separate said coatingresin, starting at a fore end thereof, from said steel pipe and seversaid coating resin along said incision lines and away from said steelpipe into at least two pieces.
 13. A method to separate and recoversteel pipe and coating resin from resin-coated steel pipe according toclaim 2 characterized in that by means of high-frequency inductionheating, said steel pipe is heated in such a manner that, when itreaches said separating mechanism located at an appropriate positionarrived at immediately after a heating process, said layer of saidcoating resin adjacent to said boundary of said steel pipe reaches acondition separable from said steel pipe, but at least said exteriorside of said outer layer of said coating resin is kept under atemperature at which softening occurs.
 14. A method to separate andrecover steel pipe and coating resin from resin-coated steel pipeaccording to claim 5 characterized in that an edge angle of saidincision blades is about 30 degrees or less.